256730657568 has 384 divisors, whose sum is σ = 893068001280. Its totient is φ = 62556779520.

The previous prime is 256730657539. The next prime is 256730657621. The reversal of 256730657568 is 865756037652.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14457271 + ... + 14475017.

It is an arithmetic number, because the mean of its divisors is an integer number (2325697920).

Almost surely, 2^256730657568 is an apocalyptic number.

256730657568 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 256730657568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (446534000640).

256730657568 is an abundant number, since it is smaller than the sum of its proper divisors (636337343712).

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

256730657568 is a wasteful number, since it uses less digits than its factorization.

256730657568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17900 (or 17892 counting only the distinct ones).

The product of its (nonzero) digits is 63504000, while the sum is 60.

The spelling of 256730657568 in words is "two hundred fifty-six billion, seven hundred thirty million, six hundred fifty-seven thousand, five hundred sixty-eight".