31621938 has 16 divisors (see below), whose sum is σ = 66964320. Its totient is φ = 9920576.

The previous prime is 31621901. The next prime is 31621949. The reversal of 31621938 is 83912613.

It is a junction number, because it is equal to n+sod(n) for n = 31621899 and 31621908.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154908 + ... + 155111.

It is an arithmetic number, because the mean of its divisors is an integer number (4185270).

Almost surely, 2^31621938 is an apocalyptic number.

31621938 is an abundant number, since it is smaller than the sum of its proper divisors (35342382).

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

31621938 is a wasteful number, since it uses less digits than its factorization.

31621938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310041.

The product of its digits is 7776, while the sum is 33.

The square root of 31621938 is about 5623.3386880038. The cubic root of 31621938 is about 316.2249706532.

The spelling of 31621938 in words is "thirty-one million, six hundred twenty-one thousand, nine hundred thirty-eight".