256631215434731 has 4 divisors (see below), whose sum is σ = 257467147732872. Its totient is φ = 255795283136592.

The previous prime is 256631215434703. The next prime is 256631215434773. The reversal of 256631215434731 is 137434512136652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256631215434731 - 2⁶ = 256631215434667 is a prime.

It is a super-2 number, since 2×256631215434731² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256631215434791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417966148610 + ... + 417966149223.

It is an arithmetic number, because the mean of its divisors is an integer number (64366786933218).

Almost surely, 2^{256631215434731} is an apocalyptic number.

256631215434731 is a deficient number, since it is larger than the sum of its proper divisors (835932298141).

256631215434731 is an equidigital number, since it uses as much as digits as its factorization.

256631215434731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835932298140.

The product of its digits is 10886400, while the sum is 53.

The spelling of 256631215434731 in words is "two hundred fifty-six trillion, six hundred thirty-one billion, two hundred fifteen million, four hundred thirty-four thousand, seven hundred thirty-one".