257138263 has 2 divisors, whose sum is σ = 257138264. Its totient is φ = 257138262.

The previous prime is 257138239. The next prime is 257138281. The reversal of 257138263 is 362831752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257138263 - 2²⁵ = 223583831 is a prime.

It is a super-2 number, since 2×257138263² = 132240172597314338, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257138293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128569131 + 128569132.

It is an arithmetic number, because the mean of its divisors is an integer number (128569132).

Almost surely, 2^257138263 is an apocalyptic number.

257138263 is a deficient number, since it is larger than the sum of its proper divisors (1).

257138263 is an equidigital number, since it uses as much as digits as its factorization.

257138263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 257138263 is about 16035.5312665343. The cubic root of 257138263 is about 635.9001127032.

The spelling of 257138263 in words is "two hundred fifty-seven million, one hundred thirty-eight thousand, two hundred sixty-three".