257297358391 has 2 divisors, whose sum is σ = 257297358392. Its totient is φ = 257297358390.

The previous prime is 257297358377. The next prime is 257297358403. The reversal of 257297358391 is 193853792752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257297358391 - 2²⁵ = 257263803959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257297358361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128648679195 + 128648679196.

It is an arithmetic number, because the mean of its divisors is an integer number (128648679196).

Almost surely, 2^257297358391 is an apocalyptic number.

257297358391 is a deficient number, since it is larger than the sum of its proper divisors (1).

257297358391 is an equidigital number, since it uses as much as digits as its factorization.

257297358391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28576800, while the sum is 61.

The spelling of 257297358391 in words is "two hundred fifty-seven billion, two hundred ninety-seven million, three hundred fifty-eight thousand, three hundred ninety-one".