31961728020 has 24 divisors (see below), whose sum is σ = 89492838624. Its totient is φ = 8523127456.

The previous prime is 31961727991. The next prime is 31961728121. The reversal of 31961728020 is 2082716913.

It is a self number, because there is not a number n which added to its sum of digits gives 31961728020.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 266347674 + ... + 266347793.

It is an arithmetic number, because the mean of its divisors is an integer number (3728868276).

Almost surely, 2^31961728020 is an apocalyptic number.

31961728020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31961728020 is an abundant number, since it is smaller than the sum of its proper divisors (57531110604).

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

31961728020 is a wasteful number, since it uses less digits than its factorization.

31961728020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532695479 (or 532695477 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The spelling of 31961728020 in words is "thirty-one billion, nine hundred sixty-one million, seven hundred twenty-eight thousand, twenty".