256515710626261 has 16 divisors (see below), whose sum is σ = 263765084470720. Its totient is φ = 249283160565120.

The previous prime is 256515710626247. The next prime is 256515710626267. The reversal of 256515710626261 is 162626017515652.

It is a cyclic number.

It is not a de Polignac number, because 256515710626261 - 2²³ = 256515702237653 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 (256515710626267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110965105 + ... + 113253193.

It is an arithmetic number, because the mean of its divisors is an integer number (16485317779420).

Almost surely, 2^{256515710626261} is an apocalyptic number.

It is an amenable number.

256515710626261 is a deficient number, since it is larger than the sum of its proper divisors (7249373844459).

256515710626261 is a wasteful number, since it uses less digits than its factorization.

256515710626261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2291764.

The product of its (nonzero) digits is 9072000, while the sum is 55.

The spelling of 256515710626261 in words is "two hundred fifty-six trillion, five hundred fifteen billion, seven hundred ten million, six hundred twenty-six thousand, two hundred sixty-one".