251957 has 4 divisors (see below), whose sum is σ = 266796. Its totient is φ = 237120.

The previous prime is 251947. The next prime is 251969. The reversal of 251957 is 759152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 155236 + 96721 = 394^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 251957 - 2⁴ = 251941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 251957.

It is not an unprimeable number, because it can be changed into a prime (251917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7394 + ... + 7427.

It is an arithmetic number, because the mean of its divisors is an integer number (66699).

2²⁵¹⁹⁵⁷ is an apocalyptic number.

It is an amenable number.

251957 is a deficient number, since it is larger than the sum of its proper divisors (14839).

251957 is a wasteful number, since it uses less digits than its factorization.

251957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14838.

The product of its digits is 3150, while the sum is 29.

The square root of 251957 is about 501.9531850681. The cubic root of 251957 is about 63.1600031338.

The spelling of 251957 in words is "two hundred fifty-one thousand, nine hundred fifty-seven".