256316220053721 has 40 divisors (see below), whose sum is σ = 384654419702784. Its totient is φ = 170091184633920.

The previous prime is 256316220053683. The next prime is 256316220053759. The reversal of 256316220053721 is 127350022613652.

256316220053721 is a `hidden beast` number, since 2 + 5 + 6 + 31 + 62 + 2 + 0 + 0 + 537 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (256316220053683) and next prime (256316220053759).

It is not a de Polignac number, because 256316220053721 - 2¹⁴ = 256316220037337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256316220053021) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 153372736 + ... + 155034926.

Almost surely, 2^{256316220053721} is an apocalyptic number.

It is an amenable number.

256316220053721 is a deficient number, since it is larger than the sum of its proper divisors (128338199649063).

256316220053721 is a wasteful number, since it uses less digits than its factorization.

256316220053721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1670963 (or 1670954 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The spelling of 256316220053721 in words is "two hundred fifty-six trillion, three hundred sixteen billion, two hundred twenty million, fifty-three thousand, seven hundred twenty-one".