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Cardinal | one hundred five | |||
Ordinal | 105th (one hundred fifth) | |||
Factorization | 3 × 5 × 7 | |||
Divisors | 1, 3, 5, 7, 15, 21, 35, 105 | |||
Greek numeral | ΡΕ´ | |||
Roman numeral | CV | |||
Binary | 11010012 | |||
Ternary | 102203 | |||
Senary | 2536 | |||
Octal | 1518 | |||
Duodecimal | 8912 | |||
Hexadecimal | 6916 |
105 (one hundred [and] five) is the natural number following 104 and preceding 106.
105 is a triangular number, a dodecagonal number, [1] and the first Zeisel number. [2] It is the first odd sphenic number and is the product of three consecutive prime numbers. 105 is the double factorial of 7. [3] It is also the sum of the first five square pyramidal numbers.
105 comes in the middle of the prime quadruplet (101, 103, 107, 109). The only other such numbers less than a thousand are 9, 15, 195, and 825.
105 is also the middle of the only prime sextuplet (97, 101, 103, 107, 109, 113) between the ones occurring at 7-23 and at 16057–16073. As the product of the first three odd primes () and less than the square of the next prime (11) by > 8, for , n ± 2, ± 4, and ± 8 must be prime, and n ± 6, ± 10, ± 12, and ± 14 must be composite (prime gap).[ clarification needed ]
105 is also a pseudoprime to the prime bases 13, 29, 41, 43, 71, 83, and 97. The distinct prime factors of 105 add up to 15, and so do those of 104; hence, the two numbers form a Ruth-Aaron pair under the first definition.
105 is also a number n for which is prime, for . (This even works up to , ignoring the negative sign.)
105 is the smallest integer such that the factorization of over Q includes non-zero coefficients other than . In other words, the 105th cyclotomic polynomial, Φ105, is the first with coefficients other than .
105 is the number of parallelogram polyominoes with 7 cells. [4]
105 is also:
35 (thirty-five) is the natural number following 34 and preceding 36.
1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000.
127 is the natural number following 126 and preceding 128. It is also a prime number.
500 is the natural number following 499 and preceding 501.
700 is the natural number following 699 and preceding 701.
900 is the natural number following 899 and preceding 901. It is the square of 30 and the sum of Euler's totient function for the first 54 positive integers. In base 10 it is a Harshad number. It is also the first number to be the square of a sphenic number.
2000 is a natural number following 1999 and preceding 2001.
10,000 is the natural number following 9,999 and preceding 10,001.
126 is the natural number following 125 and preceding 127.
4000 is the natural number following 3999 and preceding 4001. It is a decagonal number.
5000 is the natural number following 4999 and preceding 5001. Five thousand is the largest isogrammic number in the English language.
6000 is the natural number following 5999 and preceding 6001.
1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001. With a number, "billion" can be abbreviated as b, bil or bn.
100,000 (one hundred thousand) is the natural number following 99,999 and preceding 100,001. In scientific notation, it is written as 105.
10,000,000 is the natural number following 9,999,999 and preceding 10,000,001.
100,000,000 is the natural number following 99,999,999 and preceding 100,000,001.
288 is the natural number following 287 and preceding 289. Because 288 = 2 · 12 · 12, it may also be called "two gross" or "two dozen dozen".
20,000 is the natural number that comes after 19,999 and before 20,001.
30,000 is the natural number that comes after 29,999 and before 30,001.
80,000 is the natural number after 79,999 and before 80,001.