31820821704 has 64 divisors (see below), whose sum is σ = 101018486400. Its totient is φ = 9091662912.

The previous prime is 31820821667. The next prime is 31820821709. The reversal of 31820821704 is 40712802813.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (31820821709) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 10521247 + ... + 10524270.

It is an arithmetic number, because the mean of its divisors is an integer number (1578413850).

Almost surely, 2^31820821704 is an apocalyptic number.

It is an amenable number.

31820821704 is an abundant number, since it is smaller than the sum of its proper divisors (69197664696).

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

31820821704 is a wasteful number, since it uses less digits than its factorization.

31820821704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21045539 (or 21045529 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 31820821704 in words is "thirty-one billion, eight hundred twenty million, eight hundred twenty-one thousand, seven hundred four".