31389197920 has 48 divisors (see below), whose sum is σ = 74308198608. Its totient is φ = 12530076160.

The previous prime is 31389197911. The next prime is 31389197977. The reversal of 31389197920 is 2979198313.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121219 + ... + 278338.

It is an arithmetic number, because the mean of its divisors is an integer number (1548087471).

Almost surely, 2^31389197920 is an apocalyptic number.

It is an amenable number.

31389197920 is an abundant number, since it is smaller than the sum of its proper divisors (42919000688).

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

31389197920 is a wasteful number, since it uses less digits than its factorization.

31389197920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400063 (or 400055 counting only the distinct ones).

The product of its (nonzero) digits is 734832, while the sum is 52.

The spelling of 31389197920 in words is "thirty-one billion, three hundred eighty-nine million, one hundred ninety-seven thousand, nine hundred twenty".