257987 has 2 divisors, whose sum is σ = 257988. Its totient is φ = 257986.

The previous prime is 257981. The next prime is 257989. The reversal of 257987 is 789752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257987 - 2⁸ = 257731 is a prime.

Together with 257989, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 257987.

It is not a weakly prime, because it can be changed into another prime (257981) 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, 128993 + 128994.

It is an arithmetic number, because the mean of its divisors is an integer number (128994).

2²⁵⁷⁹⁸⁷ is an apocalyptic number.

257987 is a deficient number, since it is larger than the sum of its proper divisors (1).

257987 is an equidigital number, since it uses as much as digits as its factorization.

257987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 38.

The square root of 257987 is about 507.9242069443. The cubic root of 257987 is about 63.6598983452.

The spelling of 257987 in words is "two hundred fifty-seven thousand, nine hundred eighty-seven".