21204767620 has 48 divisors (see below), whose sum is σ = 45167270400. Its totient is φ = 8360876160.

The previous prime is 21204767569. The next prime is 21204767621. The reversal of 21204767620 is 2676740212.

It is a self number, because there is not a number n which added to its sum of digits gives 21204767620.

It is not an unprimeable number, because it can be changed into a prime (21204767621) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 986346 + ... + 1007614.

It is an arithmetic number, because the mean of its divisors is an integer number (940984800).

Almost surely, 2^21204767620 is an apocalyptic number.

21204767620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21204767620 is an abundant number, since it is smaller than the sum of its proper divisors (23962502780).

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

21204767620 is a wasteful number, since it uses less digits than its factorization.

21204767620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21988 (or 21986 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 37.

The spelling of 21204767620 in words is "twenty-one billion, two hundred four million, seven hundred sixty-seven thousand, six hundred twenty".