256732645221 has 48 divisors (see below), whose sum is σ = 403843440000. Its totient is φ = 156222297216.

The previous prime is 256732645193. The next prime is 256732645249. The reversal of 256732645221 is 122546237652.

256732645221 is a `hidden beast` number, since 2 + 5 + 67 + 3 + 2 + 64 + 522 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (256732645193) and next prime (256732645249).

It is not a de Polignac number, because 256732645221 - 2²¹ = 256730548069 is a prime.

It is a super-2 number, since 2×256732645221² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256732645121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6343576 + ... + 6383918.

It is an arithmetic number, because the mean of its divisors is an integer number (8413405000).

Almost surely, 2^256732645221 is an apocalyptic number.

It is an amenable number.

256732645221 is a deficient number, since it is larger than the sum of its proper divisors (147110794779).

256732645221 is a wasteful number, since it uses less digits than its factorization.

256732645221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40970 (or 40967 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 45.

The spelling of 256732645221 in words is "two hundred fifty-six billion, seven hundred thirty-two million, six hundred forty-five thousand, two hundred twenty-one".