251564 has 12 divisors (see below), whose sum is σ = 447888. Its totient is φ = 123600.

The previous prime is 251561. The next prime is 251567. The reversal of 251564 is 465152.

It is an interprime number because it is at equal distance from previous prime (251561) and next prime (251567).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 251564.

It is not an unprimeable number, because it can be changed into a prime (251561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272 + ... + 759.

It is an arithmetic number, because the mean of its divisors is an integer number (37324).

2²⁵¹⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

251564 is a deficient number, since it is larger than the sum of its proper divisors (196324).

251564 is a wasteful number, since it uses less digits than its factorization.

251564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096 (or 1094 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 251564 is about 501.5615615256. The cubic root of 251564 is about 63.1271472655.

The spelling of 251564 in words is "two hundred fifty-one thousand, five hundred sixty-four".