31920016 has 20 divisors (see below), whose sum is σ = 65483532. Its totient is φ = 15021056.

The previous prime is 31920013. The next prime is 31920043. The reversal of 31920016 is 61002913.

It can be written as a sum of positive squares in 2 ways, for example, as 18524416 + 13395600 = 4304^2 + 3660^2 .

It is not an unprimeable number, because it can be changed into a prime (31920013) 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 3 ways as a sum of consecutive naturals, for example, 58405 + ... + 58948.

Almost surely, 2^31920016 is an apocalyptic number.

It is an amenable number.

31920016 is an abundant number, since it is smaller than the sum of its proper divisors (33563516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31920016 is a wasteful number, since it uses less digits than its factorization.

31920016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117378 (or 117372 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 31920016 is about 5649.7801727147. The cubic root of 31920016 is about 317.2154757743.

Adding to 31920016 its reverse (61002913), we get a palindrome (92922929).

The spelling of 31920016 in words is "thirty-one million, nine hundred twenty thousand, sixteen".