256732540 has 24 divisors (see below), whose sum is σ = 542157840. Its totient is φ = 102117888.

The previous prime is 256732507. The next prime is 256732573. The reversal of 256732540 is 45237652.

It is an interprime number because it is at equal distance from previous prime (256732507) and next prime (256732573).

It is a junction number, because it is equal to n+sod(n) for n = 256732496 and 256732505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32277 + ... + 39436.

It is an arithmetic number, because the mean of its divisors is an integer number (22589910).

Almost surely, 2^256732540 is an apocalyptic number.

256732540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256732540 is an abundant number, since it is smaller than the sum of its proper divisors (285425300).

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

256732540 is a wasteful number, since it uses less digits than its factorization.

256732540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71901 (or 71899 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 34.

The square root of 256732540 is about 16022.8755222026. The cubic root of 256732540 is about 635.5654871321.

The spelling of 256732540 in words is "two hundred fifty-six million, seven hundred thirty-two thousand, five hundred forty".