257687879 has 2 divisors, whose sum is σ = 257687880. Its totient is φ = 257687878.

The previous prime is 257687849. The next prime is 257687891. The reversal of 257687879 is 978786752.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257687879 is a prime.

It is a super-3 number, since 3×257687879³ (a number of 26 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257687839) 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, 128843939 + 128843940.

It is an arithmetic number, because the mean of its divisors is an integer number (128843940).

Almost surely, 2^257687879 is an apocalyptic number.

257687879 is a deficient number, since it is larger than the sum of its proper divisors (1).

257687879 is an equidigital number, since it uses as much as digits as its factorization.

257687879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11854080, while the sum is 59.

The square root of 257687879 is about 16052.6595615804. The cubic root of 257687879 is about 636.3528550734.

The spelling of 257687879 in words is "two hundred fifty-seven million, six hundred eighty-seven thousand, eight hundred seventy-nine".