257866831 has 2 divisors, whose sum is σ = 257866832. Its totient is φ = 257866830.

The previous prime is 257866793. The next prime is 257866849. The reversal of 257866831 is 138668752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257866831 - 2²³ = 249478223 is a prime.

It is a super-2 number, since 2×257866831² = 132990605059965122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257866891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128933415 + 128933416.

It is an arithmetic number, because the mean of its divisors is an integer number (128933416).

Almost surely, 2^257866831 is an apocalyptic number.

257866831 is a deficient number, since it is larger than the sum of its proper divisors (1).

257866831 is an equidigital number, since it uses as much as digits as its factorization.

257866831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 46.

The square root of 257866831 is about 16058.2324992510. The cubic root of 257866831 is about 636.5001266047.

The spelling of 257866831 in words is "two hundred fifty-seven million, eight hundred sixty-six thousand, eight hundred thirty-one".