311315731 has 2 divisors, whose sum is σ = 311315732. Its totient is φ = 311315730.

The previous prime is 311315729. The next prime is 311315773. The reversal of 311315731 is 137513113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 311315731 - 2¹ = 311315729 is a prime.

It is a super-2 number, since 2×311315731² = 193834968736128722, which contains 22 as substring.

Together with 311315729, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 311315696 and 311315705.

It is not a weakly prime, because it can be changed into another prime (311312731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155657865 + 155657866.

It is an arithmetic number, because the mean of its divisors is an integer number (155657866).

Almost surely, 2^311315731 is an apocalyptic number.

311315731 is a deficient number, since it is larger than the sum of its proper divisors (1).

311315731 is an equidigital number, since it uses as much as digits as its factorization.

311315731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 945, while the sum is 25.

The square root of 311315731 is about 17644.1415489675. The cubic root of 311315731 is about 677.7460921604.

Adding to 311315731 its reverse (137513113), we get a palindrome (448828844).

The spelling of 311315731 in words is "three hundred eleven million, three hundred fifteen thousand, seven hundred thirty-one".