257660748217 has 16 divisors (see below), whose sum is σ = 275563411344. Its totient is φ = 240064000000.

The previous prime is 257660748211. The next prime is 257660748229. The reversal of 257660748217 is 712847066752.

It can be written as a sum of positive squares in 8 ways, for example, as 122660352441 + 135000395776 = 350229^2 + 367424^2 .

It is a cyclic number.

It is not a de Polignac number, because 257660748217 - 2⁷ = 257660748089 is a prime.

It is a super-2 number, since 2×257660748217² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (257660748211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20771217 + ... + 20783617.

It is an arithmetic number, because the mean of its divisors is an integer number (17222713209).

Almost surely, 2^257660748217 is an apocalyptic number.

It is an amenable number.

257660748217 is a deficient number, since it is larger than the sum of its proper divisors (17902663127).

257660748217 is a wasteful number, since it uses less digits than its factorization.

257660748217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24620.

The product of its (nonzero) digits is 7902720, while the sum is 55.

The spelling of 257660748217 in words is "two hundred fifty-seven billion, six hundred sixty million, seven hundred forty-eight thousand, two hundred seventeen".