31820637992 has 64 divisors (see below), whose sum is σ = 70161638400. Its totient is φ = 13338512640.

The previous prime is 31820637971. The next prime is 31820638001. The reversal of 31820637992 is 29973602813.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 31820637992.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1230734 + ... + 1256322.

It is an arithmetic number, because the mean of its divisors is an integer number (1096275600).

Almost surely, 2^31820637992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31820637992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35080819200).

31820637992 is an abundant number, since it is smaller than the sum of its proper divisors (38341000408).

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

31820637992 is a wasteful number, since it uses less digits than its factorization.

31820637992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26706 (or 26702 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 50.

The spelling of 31820637992 in words is "thirty-one billion, eight hundred twenty million, six hundred thirty-seven thousand, nine hundred ninety-two".