316123137721 has 2 divisors, whose sum is σ = 316123137722. Its totient is φ = 316123137720.

The previous prime is 316123137703. The next prime is 316123137779. The reversal of 316123137721 is 127731321613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174419828496 + 141703309225 = 417636^2 + 376435^2 .

It is a cyclic number.

It is not a de Polignac number, because 316123137721 - 2⁷ = 316123137593 is a prime.

It is not a weakly prime, because it can be changed into another prime (316133137721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158061568860 + 158061568861.

It is an arithmetic number, because the mean of its divisors is an integer number (158061568861).

Almost surely, 2^316123137721 is an apocalyptic number.

It is an amenable number.

316123137721 is a deficient number, since it is larger than the sum of its proper divisors (1).

316123137721 is an equidigital number, since it uses as much as digits as its factorization.

316123137721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 37.

The spelling of 316123137721 in words is "three hundred sixteen billion, one hundred twenty-three million, one hundred thirty-seven thousand, seven hundred twenty-one".