257244816681 has 64 divisors (see below), whose sum is σ = 408859084800. Its totient is φ = 159435511488.

The previous prime is 257244816659. The next prime is 257244816707. The reversal of 257244816681 is 186618442752.

257244816681 is a `hidden beast` number, since 2 + 5 + 7 + 24 + 481 + 66 + 81 = 666.

It is not a de Polignac number, because 257244816681 - 2¹³ = 257244808489 is a prime.

It is a super-2 number, since 2×257244816681² (a number of 24 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (257244816611) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23408070 + ... + 23419056.

It is an arithmetic number, because the mean of its divisors is an integer number (6388423200).

Almost surely, 2^257244816681 is an apocalyptic number.

It is an amenable number.

257244816681 is a deficient number, since it is larger than the sum of its proper divisors (151614268119).

257244816681 is a wasteful number, since it uses less digits than its factorization.

257244816681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12075 (or 12069 counting only the distinct ones).

The product of its digits is 5160960, while the sum is 54.

The spelling of 257244816681 in words is "two hundred fifty-seven billion, two hundred forty-four million, eight hundred sixteen thousand, six hundred eighty-one".