312640331 has 2 divisors, whose sum is σ = 312640332. Its totient is φ = 312640330.

The previous prime is 312640313. The next prime is 312640337. The reversal of 312640331 is 133046213.

Together with previous prime (312640313) 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 312640331 - 2¹⁴ = 312623947 is a prime.

It is a super-2 number, since 2×312640331² = 195487953135579122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 312640297 and 312640306.

It is not a weakly prime, because it can be changed into another prime (312640337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156320165 + 156320166.

It is an arithmetic number, because the mean of its divisors is an integer number (156320166).

Almost surely, 2^312640331 is an apocalyptic number.

312640331 is a deficient number, since it is larger than the sum of its proper divisors (1).

312640331 is an equidigital number, since it uses as much as digits as its factorization.

312640331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 312640331 is about 17681.6382442352. The cubic root of 312640331 is about 678.7059667980.

Adding to 312640331 its reverse (133046213), we get a palindrome (445686544).

The spelling of 312640331 in words is "three hundred twelve million, six hundred forty thousand, three hundred thirty-one".