256385720 has 16 divisors (see below), whose sum is σ = 576867960. Its totient is φ = 102554272.

The previous prime is 256385719. The next prime is 256385747. The reversal of 256385720 is 27583652.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3204782 + ... + 3204861.

Almost surely, 2^256385720 is an apocalyptic number.

256385720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256385720 is an abundant number, since it is smaller than the sum of its proper divisors (320482240).

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

256385720 is a wasteful number, since it uses less digits than its factorization.

256385720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6409654 (or 6409650 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 256385720 is about 16012.0492130146. The cubic root of 256385720 is about 635.2791630130.

The spelling of 256385720 in words is "two hundred fifty-six million, three hundred eighty-five thousand, seven hundred twenty".