31920044 has 36 divisors (see below), whose sum is σ = 63148176. Its totient is φ = 14084928.

The previous prime is 31920043. The next prime is 31920071. The reversal of 31920044 is 44002913.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31920043) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14522 + ... + 16574.

It is an arithmetic number, because the mean of its divisors is an integer number (1754116).

Almost surely, 2^31920044 is an apocalyptic number.

It is an amenable number.

31920044 is a deficient number, since it is larger than the sum of its proper divisors (31228132).

31920044 is a wasteful number, since it uses less digits than its factorization.

31920044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2106 (or 2091 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 31920044 is about 5649.7826506867. The cubic root of 31920044 is about 317.2155685273.

Adding to 31920044 its reverse (44002913), we get a palindrome (75922957).

The spelling of 31920044 in words is "thirty-one million, nine hundred twenty thousand, forty-four".