257163979 has 2 divisors, whose sum is σ = 257163980. Its totient is φ = 257163978.

The previous prime is 257163971. The next prime is 257164001. The reversal of 257163979 is 979361752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257163979 - 2³ = 257163971 is a prime.

It is a super-2 number, since 2×257163979² = 132266624190224882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257163971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128581989 + 128581990.

It is an arithmetic number, because the mean of its divisors is an integer number (128581990).

Almost surely, 2^257163979 is an apocalyptic number.

257163979 is a deficient number, since it is larger than the sum of its proper divisors (1).

257163979 is an equidigital number, since it uses as much as digits as its factorization.

257163979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 714420, while the sum is 49.

The square root of 257163979 is about 16036.3330908285. Note that the first 3 decimals coincide. The cubic root of 257163979 is about 635.9213104588.

The spelling of 257163979 in words is "two hundred fifty-seven million, one hundred sixty-three thousand, nine hundred seventy-nine".