31994865137 has 2 divisors, whose sum is σ = 31994865138. Its totient is φ = 31994865136.

The previous prime is 31994865107. The next prime is 31994865169. The reversal of 31994865137 is 73156849913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26284191376 + 5710673761 = 162124^2 + 75569^2 .

It is a cyclic number.

It is not a de Polignac number, because 31994865137 - 2¹⁸ = 31994602993 is a prime.

It is not a weakly prime, because it can be changed into another prime (31994865107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15997432568 + 15997432569.

It is an arithmetic number, because the mean of its divisors is an integer number (15997432569).

Almost surely, 2^31994865137 is an apocalyptic number.

It is an amenable number.

31994865137 is a deficient number, since it is larger than the sum of its proper divisors (1).

31994865137 is an equidigital number, since it uses as much as digits as its factorization.

31994865137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 56.

The spelling of 31994865137 in words is "thirty-one billion, nine hundred ninety-four million, eight hundred sixty-five thousand, one hundred thirty-seven".