31999939 has 2 divisors, whose sum is σ = 31999940. Its totient is φ = 31999938.

The previous prime is 31999927. The next prime is 32000011. The reversal of 31999939 is 93999913.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31999939 - 2⁵ = 31999907 is a prime.

It is not a weakly prime, because it can be changed into another prime (31999909) 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, 15999969 + 15999970.

It is an arithmetic number, because the mean of its divisors is an integer number (15999970).

Almost surely, 2^31999939 is an apocalyptic number.

31999939 is a deficient number, since it is larger than the sum of its proper divisors (1).

31999939 is an equidigital number, since it uses as much as digits as its factorization.

31999939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 531441, while the sum is 52.

The square root of 31999939 is about 5656.8488578006. The cubic root of 31999939 is about 317.4800086613.

The spelling of 31999939 in words is "thirty-one million, nine hundred ninety-nine thousand, nine hundred thirty-nine".