31807138 has 16 divisors (see below), whose sum is σ = 52709760. Its totient is φ = 14274000.

The previous prime is 31807133. The next prime is 31807151. The reversal of 31807138 is 83170813.

It is not an unprimeable number, because it can be changed into a prime (31807133) 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 in 7 ways as a sum of consecutive naturals, for example, 7413 + ... + 10888.

It is an arithmetic number, because the mean of its divisors is an integer number (3294360).

Almost surely, 2^31807138 is an apocalyptic number.

31807138 is a deficient number, since it is larger than the sum of its proper divisors (20902622).

31807138 is a wasteful number, since it uses less digits than its factorization.

31807138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18393.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 31807138 is about 5639.7817333652. The cubic root of 31807138 is about 316.8411136082.

The spelling of 31807138 in words is "thirty-one million, eight hundred seven thousand, one hundred thirty-eight".