256731930 has 288 divisors, whose sum is σ = 872936064. Its totient is φ = 52907904.

The previous prime is 256731919. The next prime is 256731961. The reversal of 256731930 is 39137652.

256731930 is a `hidden beast` number, since 2 + 567 + 3 + 1 + 93 + 0 = 666.

It is a super-2 number, since 2×256731930² = 131822567763049800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 5970489 + ... + 5970531.

It is an arithmetic number, because the mean of its divisors is an integer number (3031028).

Almost surely, 2^256731930 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256731930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436468032).

256731930 is an abundant number, since it is smaller than the sum of its proper divisors (616204134).

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

256731930 is an equidigital number, since it uses as much as digits as its factorization.

256731930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 36.

The square root of 256731930 is about 16022.8564869064. The cubic root of 256731930 is about 635.5649837609.

The spelling of 256731930 in words is "two hundred fifty-six million, seven hundred thirty-one thousand, nine hundred thirty".