256538688 has 224 divisors, whose sum is σ = 832567296. Its totient is φ = 68124672.

The previous prime is 256538647. The next prime is 256538693. The reversal of 256538688 is 886835652.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×256538688² = 131624196881522688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256538688.

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, 1329120 + ... + 1329312.

Almost surely, 2^256538688 is an apocalyptic number.

256538688 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 256538688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (416283648).

256538688 is an abundant number, since it is smaller than the sum of its proper divisors (576028608).

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

256538688 is a wasteful number, since it uses less digits than its factorization.

256538688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 271 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 51.

The square root of 256538688 is about 16016.8251535690. The cubic root of 256538688 is about 635.4054805826.

The spelling of 256538688 in words is "two hundred fifty-six million, five hundred thirty-eight thousand, six hundred eighty-eight".