257868139 has 2 divisors, whose sum is σ = 257868140. Its totient is φ = 257868138.

The previous prime is 257868101. The next prime is 257868197. The reversal of 257868139 is 931868752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257868139 - 2⁷ = 257868011 is a prime.

It is a super-2 number, since 2×257868139² = 132991954222646642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 257868092 and 257868101.

It is not a weakly prime, because it can be changed into another prime (257868239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128934069 + 128934070.

It is an arithmetic number, because the mean of its divisors is an integer number (128934070).

Almost surely, 2^257868139 is an apocalyptic number.

257868139 is a deficient number, since it is larger than the sum of its proper divisors (1).

257868139 is an equidigital number, since it uses as much as digits as its factorization.

257868139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 49.

The square root of 257868139 is about 16058.2732259730. The cubic root of 257868139 is about 636.5012027943.

The spelling of 257868139 in words is "two hundred fifty-seven million, eight hundred sixty-eight thousand, one hundred thirty-nine".