256831440768 has 320 divisors, whose sum is σ = 887850897120. Its totient is φ = 72176209920.

The previous prime is 256831440751. The next prime is 256831440779. The reversal of 256831440768 is 867044138652.

It is a happy number.

256831440768 is a `hidden beast` number, since 2 + 56 + 83 + 1 + 440 + 76 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4398130 + ... + 4456142.

Almost surely, 2^256831440768 is an apocalyptic number.

256831440768 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256831440768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (443925448560).

256831440768 is an abundant number, since it is smaller than the sum of its proper divisors (631019456352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256831440768 is an equidigital number, since it uses as much as digits as its factorization.

256831440768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58107 (or 58086 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 54.

The spelling of 256831440768 in words is "two hundred fifty-six billion, eight hundred thirty-one million, four hundred forty thousand, seven hundred sixty-eight".