31787038920 has 384 divisors, whose sum is σ = 122703033600. Its totient is φ = 6524872704.

The previous prime is 31787038861. The next prime is 31787038937. The reversal of 31787038920 is 2983078713.

It is a self number, because there is not a number n which added to its sum of digits gives 31787038920.

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 95 ways as a sum of consecutive naturals, for example, 2822661 + ... + 2833899.

It is an arithmetic number, because the mean of its divisors is an integer number (319539150).

Almost surely, 2^31787038920 is an apocalyptic number.

31787038920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31787038920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61351516800).

31787038920 is an abundant number, since it is smaller than the sum of its proper divisors (90915994680).

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

31787038920 is a wasteful number, since it uses less digits than its factorization.

31787038920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11317 (or 11306 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The spelling of 31787038920 in words is "thirty-one billion, seven hundred eighty-seven million, thirty-eight thousand, nine hundred twenty".