9939997931 has 2 divisors, whose sum is σ = 9939997932. Its totient is φ = 9939997930.

The previous prime is 9939997901. The next prime is 9939997967. The reversal of 9939997931 is 1397999399.

It is a weak prime.

It is an emirp because it is prime and its reverse (1397999399) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9939997931 - 2¹⁸ = 9939735787 is a prime.

It is a super-2 number, since 2×9939997931² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9939997901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4969998965 + 4969998966.

It is an arithmetic number, because the mean of its divisors is an integer number (4969998966).

Almost surely, 2^9939997931 is an apocalyptic number.

9939997931 is a deficient number, since it is larger than the sum of its proper divisors (1).

9939997931 is an equidigital number, since it uses as much as digits as its factorization.

9939997931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33480783, while the sum is 68.

The square root of 9939997931 is about 99699.5382687402. The cubic root of 9939997931 is about 2150.1170248903.

The spelling of 9939997931 in words is "nine billion, nine hundred thirty-nine million, nine hundred ninety-seven thousand, nine hundred thirty-one".