31981821380 has 24 divisors (see below), whose sum is σ = 67200080640. Its totient is φ = 12785441760.

The previous prime is 31981821337. The next prime is 31981821413. The reversal of 31981821380 is 8312818913.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419366 + ... + 489725.

It is an arithmetic number, because the mean of its divisors is an integer number (2800003360).

Almost surely, 2^31981821380 is an apocalyptic number.

It is an amenable number.

31981821380 is an abundant number, since it is smaller than the sum of its proper divisors (35218259260).

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

31981821380 is a wasteful number, since it uses less digits than its factorization.

31981821380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910859 (or 910857 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 44.

The spelling of 31981821380 in words is "thirty-one billion, nine hundred eighty-one million, eight hundred twenty-one thousand, three hundred eighty".