31138913 has 8 divisors (see below), whose sum is σ = 33616128. Its totient is φ = 28673424.

The previous prime is 31138907. The next prime is 31138927. The reversal of 31138913 is 31983113.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31138913 - 2¹⁰ = 31137889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31138903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3056 + ... + 8462.

It is an arithmetic number, because the mean of its divisors is an integer number (4202016).

Almost surely, 2^31138913 is an apocalyptic number.

It is an amenable number.

31138913 is a deficient number, since it is larger than the sum of its proper divisors (2477215).

31138913 is a wasteful number, since it uses less digits than its factorization.

31138913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5863.

The product of its digits is 1944, while the sum is 29.

The square root of 31138913 is about 5580.2251746681. The cubic root of 31138913 is about 314.6065904164.

The spelling of 31138913 in words is "thirty-one million, one hundred thirty-eight thousand, nine hundred thirteen".