31939013 has 4 divisors (see below), whose sum is σ = 31960428. Its totient is φ = 31917600.

The previous prime is 31938953. The next prime is 31939027. The reversal of 31939013 is 31093913.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6315169 + 25623844 = 2513^2 + 5062^2 .

It is a cyclic number.

It is not a de Polignac number, because 31939013 - 2¹⁰ = 31937989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31939213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8288 + ... + 11513.

It is an arithmetic number, because the mean of its divisors is an integer number (7990107).

Almost surely, 2^31939013 is an apocalyptic number.

It is an amenable number.

31939013 is a deficient number, since it is larger than the sum of its proper divisors (21415).

31939013 is a wasteful number, since it uses less digits than its factorization.

31939013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21414.

The product of its (nonzero) digits is 2187, while the sum is 29.

The square root of 31939013 is about 5651.4611385021. The cubic root of 31939013 is about 317.2783929035.

The spelling of 31939013 in words is "thirty-one million, nine hundred thirty-nine thousand, thirteen".