311665513 has 2 divisors, whose sum is σ = 311665514. Its totient is φ = 311665512.

The previous prime is 311665511. The next prime is 311665517. The reversal of 311665513 is 315566113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 299013264 + 12652249 = 17292^2 + 3557^2 .

It is a cyclic number.

It is not a de Polignac number, because 311665513 - 2¹ = 311665511 is a prime.

Together with 311665511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (311665511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155832756 + 155832757.

It is an arithmetic number, because the mean of its divisors is an integer number (155832757).

Almost surely, 2^311665513 is an apocalyptic number.

It is an amenable number.

311665513 is a deficient number, since it is larger than the sum of its proper divisors (1).

311665513 is an equidigital number, since it uses as much as digits as its factorization.

311665513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8100, while the sum is 31.

The square root of 311665513 is about 17654.0508949079. The cubic root of 311665513 is about 677.9998266925. Note that the first 3 decimals are identical.

The spelling of 311665513 in words is "three hundred eleven million, six hundred sixty-five thousand, five hundred thirteen".