21604484776 has 16 divisors (see below), whose sum is σ = 46295324640. Its totient is φ = 9259064880.

The previous prime is 21604484771. The next prime is 21604484819. The reversal of 21604484776 is 67748440612.

It is not an unprimeable number, because it can be changed into a prime (21604484771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192897130 + ... + 192897241.

It is an arithmetic number, because the mean of its divisors is an integer number (2893457790).

Almost surely, 2^21604484776 is an apocalyptic number.

It is an amenable number.

21604484776 is an abundant number, since it is smaller than the sum of its proper divisors (24690839864).

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

21604484776 is a wasteful number, since it uses less digits than its factorization.

21604484776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385794384 (or 385794380 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 49.

The spelling of 21604484776 in words is "twenty-one billion, six hundred four million, four hundred eighty-four thousand, seven hundred seventy-six".