257715 has 32 divisors (see below), whose sum is σ = 483840. Its totient is φ = 129888.

The previous prime is 257713. The next prime is 257717. The reversal of 257715 is 517752.

It is an interprime number because it is at equal distance from previous prime (257713) and next prime (257717).

It is not a de Polignac number, because 257715 - 2¹ = 257713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (257711) 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 in 31 ways as a sum of consecutive naturals, for example, 3064 + ... + 3146.

It is an arithmetic number, because the mean of its divisors is an integer number (15120).

2²⁵⁷⁷¹⁵ is an apocalyptic number.

257715 is a deficient number, since it is larger than the sum of its proper divisors (226125).

257715 is a wasteful number, since it uses less digits than its factorization.

257715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 114 counting only the distinct ones).

The product of its digits is 2450, while the sum is 27.

The square root of 257715 is about 507.6563798476. The cubic root of 257715 is about 63.6375179135.

The spelling of 257715 in words is "two hundred fifty-seven thousand, seven hundred fifteen".