257717476021 has 2 divisors, whose sum is σ = 257717476022. Its totient is φ = 257717476020.

The previous prime is 257717476013. The next prime is 257717476033. The reversal of 257717476021 is 120674717752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228853164996 + 28864311025 = 478386^2 + 169895^2 .

It is a cyclic number.

It is not a de Polignac number, because 257717476021 - 2³ = 257717476013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257717479021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128858738010 + 128858738011.

It is an arithmetic number, because the mean of its divisors is an integer number (128858738011).

Almost surely, 2^257717476021 is an apocalyptic number.

It is an amenable number.

257717476021 is a deficient number, since it is larger than the sum of its proper divisors (1).

257717476021 is an equidigital number, since it uses as much as digits as its factorization.

257717476021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152480, while the sum is 49.

The spelling of 257717476021 in words is "two hundred fifty-seven billion, seven hundred seventeen million, four hundred seventy-six thousand, twenty-one".