31383920 has 20 divisors (see below), whose sum is σ = 72967800. Its totient is φ = 12553536.

The previous prime is 31383907. The next prime is 31383931. The reversal of 31383920 is 2938313.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196070 + ... + 196229.

It is an arithmetic number, because the mean of its divisors is an integer number (3648390).

Almost surely, 2^31383920 is an apocalyptic number.

It is an amenable number.

31383920 is an abundant number, since it is smaller than the sum of its proper divisors (41583880).

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

31383920 is a wasteful number, since it uses less digits than its factorization.

31383920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392312 (or 392306 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 31383920 is about 5602.1353071842. The cubic root of 31383920 is about 315.4295642703.

The spelling of 31383920 in words is "thirty-one million, three hundred eighty-three thousand, nine hundred twenty".