Related Research Articles
81 (eighty-one) is the natural number following 80 and preceding 82.
82 (eighty-two) is the natural number following 81 and preceding 83.
74 (seventy-four) is the natural number following 73 and preceding 75.
52 (fifty-two) is the natural number following 51 and preceding 53.
91 (ninety-one) is the natural number following 90 and preceding 92.
93 (ninety-three) is the natural number following 92 and preceding 94.
500 is the natural number following 499 and preceding 501.
In mathematics, an aliquot sequence is a sequence of positive integers in which each term is the sum of the proper divisors of the previous term. If the sequence reaches the number 1, it ends, since the sum of the proper divisors of 1 is 0.
In mathematics, an untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer. That is, these numbers are not in the image of the aliquot sum function. Their study goes back at least to Abu Mansur al-Baghdadi, who observed that both 2 and 5 are untouchable.
124 is the natural number following 123 and preceding 125.
146 is the natural number following 145 and preceding 147.
230 is the natural number following 229 and preceding 231.
240 is the natural number following 239 and preceding 241.
238 is the natural number following 237 and preceding 239.
245 is the natural number following 244 and preceding 246.
246 is the natural number following 245 and preceding 247.
249 is the natural number following 248 and preceding 250.
In number theory, the aliquot sums(n) of a positive integer n is the sum of all proper divisors of n, that is, all divisors of n other than n itself. That is,
262 is a natural number preceded by the number 261 and followed by 263. It has the prime factorization 2·131.
304 is the natural number following 303 and preceding 305.