257536397 has 2 divisors, whose sum is σ = 257536398. Its totient is φ = 257536396.

The previous prime is 257536387. The next prime is 257536399. The reversal of 257536397 is 793635752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199685161 + 57851236 = 14131^2 + 7606^2 .

It is a cyclic number.

It is not a de Polignac number, because 257536397 - 2⁶ = 257536333 is a prime.

Together with 257536399, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257536399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128768198 + 128768199.

It is an arithmetic number, because the mean of its divisors is an integer number (128768199).

Almost surely, 2^257536397 is an apocalyptic number.

It is an amenable number.

257536397 is a deficient number, since it is larger than the sum of its proper divisors (1).

257536397 is an equidigital number, since it uses as much as digits as its factorization.

257536397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1190700, while the sum is 47.

The square root of 257536397 is about 16047.9405843865. The cubic root of 257536397 is about 636.2281371413.

The spelling of 257536397 in words is "two hundred fifty-seven million, five hundred thirty-six thousand, three hundred ninety-seven".