251591 has 8 divisors (see below), whose sum is σ = 264384. Its totient is φ = 239200.

The previous prime is 251567. The next prime is 251609. The reversal of 251591 is 195152.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 251591 - 2⁶ = 251527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2441 + ... + 2541.

It is an arithmetic number, because the mean of its divisors is an integer number (33048).

2²⁵¹⁵⁹¹ is an apocalyptic number.

251591 is a deficient number, since it is larger than the sum of its proper divisors (12793).

251591 is a wasteful number, since it uses less digits than its factorization.

251591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201.

The product of its digits is 450, while the sum is 23.

The square root of 251591 is about 501.5884767416. The cubic root of 251591 is about 63.1294056331.

The spelling of 251591 in words is "two hundred fifty-one thousand, five hundred ninety-one".