251315231 has 2 divisors, whose sum is σ = 251315232. Its totient is φ = 251315230.

The previous prime is 251315213. The next prime is 251315243. The reversal of 251315231 is 132513152.

It is a happy number.

Together with previous prime (251315213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251315231 - 2¹⁴ = 251298847 is a prime.

It is a super-2 number, since 2×251315231² = 126318690665166722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 251315197 and 251315206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251315531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125657615 + 125657616.

It is an arithmetic number, because the mean of its divisors is an integer number (125657616).

Almost surely, 2^251315231 is an apocalyptic number.

251315231 is a deficient number, since it is larger than the sum of its proper divisors (1).

251315231 is an equidigital number, since it uses as much as digits as its factorization.

251315231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 900, while the sum is 23.

The square root of 251315231 is about 15852.9249982456. The cubic root of 251315231 is about 631.0633181137.

Adding to 251315231 its reverse (132513152), we get a palindrome (383828383).

The spelling of 251315231 in words is "two hundred fifty-one million, three hundred fifteen thousand, two hundred thirty-one".