21619865604 has 24 divisors (see below), whose sum is σ = 51809769088. Its totient is φ = 7011848160.

The previous prime is 21619865599. The next prime is 21619865621. The reversal of 21619865604 is 40656891612.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24346252 + ... + 24347139.

Almost surely, 2^21619865604 is an apocalyptic number.

It is an amenable number.

21619865604 is an abundant number, since it is smaller than the sum of its proper divisors (30189903484).

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

21619865604 is a wasteful number, since it uses less digits than its factorization.

21619865604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48693435 (or 48693433 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 48.

The spelling of 21619865604 in words is "twenty-one billion, six hundred nineteen million, eight hundred sixty-five thousand, six hundred four".