256921080 has 128 divisors (see below), whose sum is σ = 836136000. Its totient is φ = 62779392.

The previous prime is 256921069. The next prime is 256921099. The reversal of 256921080 is 80129652.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244396 + ... + 245444.

Almost surely, 2^256921080 is an apocalyptic number.

256921080 is a gapful number since it is divisible by the number (20) 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 256921080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (418068000).

256921080 is an abundant number, since it is smaller than the sum of its proper divisors (579214920).

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

256921080 is a wasteful number, since it uses less digits than its factorization.

256921080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233 (or 1229 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 256921080 is about 16028.7579057143. The cubic root of 256921080 is about 635.7210318808.

The spelling of 256921080 in words is "two hundred fifty-six million, nine hundred twenty-one thousand, eighty".