256611512621173 has 8 divisors (see below), whose sum is σ = 271708642881792. Its totient is φ = 241514641849536.

The previous prime is 256611512621161. The next prime is 256611512621221. The reversal of 256611512621173 is 371126215116652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-256611512621173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256611512621873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62834415 + ... + 66793612.

It is an arithmetic number, because the mean of its divisors is an integer number (33963580360224).

Almost surely, 2^{256611512621173} is an apocalyptic number.

It is an amenable number.

256611512621173 is a deficient number, since it is larger than the sum of its proper divisors (15097130260619).

256611512621173 is a wasteful number, since it uses less digits than its factorization.

256611512621173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129744491.

The product of its digits is 907200, while the sum is 49.

The spelling of 256611512621173 in words is "two hundred fifty-six trillion, six hundred eleven billion, five hundred twelve million, six hundred twenty-one thousand, one hundred seventy-three".