31931013 has 8 divisors (see below), whose sum is σ = 43087968. Its totient is φ = 21030704.

The previous prime is 31930979. The next prime is 31931027. The reversal of 31931013 is 31013913.

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

It is a cyclic number.

It is not a de Polignac number, because 31931013 - 2⁸ = 31930757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31931033) 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, 63870 + ... + 64367.

It is an arithmetic number, because the mean of its divisors is an integer number (5385996).

Almost surely, 2^31931013 is an apocalyptic number.

It is an amenable number.

31931013 is a deficient number, since it is larger than the sum of its proper divisors (11156955).

31931013 is a wasteful number, since it uses less digits than its factorization.

31931013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128323.

The product of its (nonzero) digits is 243, while the sum is 21.

The square root of 31931013 is about 5650.7533126124. The cubic root of 31931013 is about 317.2519003389.

Adding to 31931013 its reverse (31013913), we get a palindrome (62944926).

The spelling of 31931013 in words is "thirty-one million, nine hundred thirty-one thousand, thirteen".