251440131 has 4 divisors (see below), whose sum is σ = 335253512. Its totient is φ = 167626752.

The previous prime is 251440067. The next prime is 251440139. The reversal of 251440131 is 131044152.

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

It is not a de Polignac number, because 251440131 - 2⁶ = 251440067 is a prime.

It is a super-2 number, since 2×251440131² = 126444278954594322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 251440098 and 251440107.

It is not an unprimeable number, because it can be changed into a prime (251440139) 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, 41906686 + ... + 41906691.

It is an arithmetic number, because the mean of its divisors is an integer number (83813378).

Almost surely, 2^251440131 is an apocalyptic number.

251440131 is a deficient number, since it is larger than the sum of its proper divisors (83813381).

251440131 is an equidigital number, since it uses as much as digits as its factorization.

251440131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83813380.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 251440131 is about 15856.8638450357. The cubic root of 251440131 is about 631.1678438843.

Adding to 251440131 its reverse (131044152), we get a palindrome (382484283).

The spelling of 251440131 in words is "two hundred fifty-one million, four hundred forty thousand, one hundred thirty-one".