31910139 has 32 divisors (see below), whose sum is σ = 52704000. Its totient is φ = 18963072.

The previous prime is 31910113. The next prime is 31910143. The reversal of 31910139 is 93101913.

It is not a de Polignac number, because 31910139 - 2⁵ = 31910107 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (31910189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6892 + ... + 10550.

It is an arithmetic number, because the mean of its divisors is an integer number (1647000).

Almost surely, 2^31910139 is an apocalyptic number.

31910139 is a deficient number, since it is larger than the sum of its proper divisors (20793861).

31910139 is a wasteful number, since it uses less digits than its factorization.

31910139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3704 (or 3698 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 27.

The square root of 31910139 is about 5648.9060002801. The cubic root of 31910139 is about 317.1827537724.

The spelling of 31910139 in words is "thirty-one million, nine hundred ten thousand, one hundred thirty-nine".