257136779 has 2 divisors, whose sum is σ = 257136780. Its totient is φ = 257136778.

The previous prime is 257136767. The next prime is 257136799. The reversal of 257136779 is 977631752.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257136779 is a prime.

It is a super-2 number, since 2×257136779² = 132238646228989682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257136749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128568389 + 128568390.

It is an arithmetic number, because the mean of its divisors is an integer number (128568390).

Almost surely, 2^257136779 is an apocalyptic number.

257136779 is a deficient number, since it is larger than the sum of its proper divisors (1).

257136779 is an equidigital number, since it uses as much as digits as its factorization.

257136779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 555660, while the sum is 47.

The square root of 257136779 is about 16035.4849942245. The cubic root of 257136779 is about 635.8988893956.

The spelling of 257136779 in words is "two hundred fifty-seven million, one hundred thirty-six thousand, seven hundred seventy-nine".