256611502542641 has 4 divisors (see below), whose sum is σ = 256894425920112. Its totient is φ = 256328579165172.

The previous prime is 256611502542607. The next prime is 256611502542643. The reversal of 256611502542641 is 146245205116652.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256611502542641 - 2²⁶ = 256611435433777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256611502542641.

It is not an unprimeable number, because it can be changed into a prime (256611502542643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141461687375 + ... + 141461689188.

It is an arithmetic number, because the mean of its divisors is an integer number (64223606480028).

Almost surely, 2^{256611502542641} is an apocalyptic number.

It is an amenable number.

256611502542641 is a deficient number, since it is larger than the sum of its proper divisors (282923377471).

256611502542641 is an equidigital number, since it uses as much as digits as its factorization.

256611502542641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282923377470.

The product of its (nonzero) digits is 3456000, while the sum is 50.

The spelling of 256611502542641 in words is "two hundred fifty-six trillion, six hundred eleven billion, five hundred two million, five hundred forty-two thousand, six hundred forty-one".