| ||||
|---|---|---|---|---|
| Cardinal | two hundred ten | |||
| Ordinal | 210th (two hundred tenth) | |||
| Factorization | 2 × 3 × 5 × 7 | |||
| Divisors | 1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210 | |||
| Greek numeral | ΣΙ´ | |||
| Roman numeral | CCX, ccx | |||
| Binary | 110100102 | |||
| Ternary | 212103 | |||
| Senary | 5506 | |||
| Octal | 3228 | |||
| Duodecimal | 15612 | |||
| Hexadecimal | D216 | |||
210 (two hundred [and] ten) is the natural number following 209 and preceding 211.
210 is an abundant number, [1] and Harshad number. It is the product of the first four prime numbers (2, 3, 5, and 7), and thus a primorial, [2] where it is the least common multiple of these four prime numbers. 210 is the first primorial number greater than 2 which is not adjacent to 2 primes (211 is prime, but 209 is not).
It is the sum of eight consecutive prime numbers, between 13 and the thirteenth prime number: 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 = 210. [3]
It is the 20th triangular number (following 190 and preceding 231), [4] a pentagonal number (following 176 and preceding 247), [5] and the second smallest to be both triangular and pentagonal (the first is 1; the third is 40755). [3]
It is also an idoneal number, a pentatope number, a pronic number, and an untouchable number. 210 is also the third 71-gonal number, preceding 418. [3]
210 is index n = 7 in the number of ways to pair up {1, ..., 2n} so that the sum of each pair is prime; i.e., in {1, ..., 14}. [6] [7]
It is the largest number n where the number of distinct representations of n as the sum of two primes is at most the number of primes in the interval [n/2 , n − 2]. [8]