256886961408 has 720 divisors, whose sum is σ = 959814979200. Its totient is φ = 66388377600.

The previous prime is 256886961389. The next prime is 256886961437. The reversal of 256886961408 is 804169688652.

256886961408 is a `hidden beast` number, since 2 + 5 + 6 + 8 + 8 + 6 + 9 + 614 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 557238298 + ... + 557238758.

It is an arithmetic number, because the mean of its divisors is an integer number (1333076360).

Almost surely, 2^256886961408 is an apocalyptic number.

256886961408 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 256886961408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (479907489600).

256886961408 is an abundant number, since it is smaller than the sum of its proper divisors (702928017792).

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

256886961408 is a wasteful number, since it uses less digits than its factorization.

256886961408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 833 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 63.

The spelling of 256886961408 in words is "two hundred fifty-six billion, eight hundred eighty-six million, nine hundred sixty-one thousand, four hundred eight".