21951988604 has 48 divisors (see below), whose sum is σ = 47723171328. Its totient is φ = 8603126208.

The previous prime is 21951988571. The next prime is 21951988621. The reversal of 21951988604 is 40688915912.

It is a congruent number.

It is an unprimeable number.

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, 242864 + ... + 320759.

It is an arithmetic number, because the mean of its divisors is an integer number (994232736).

Almost surely, 2^21951988604 is an apocalyptic number.

It is an amenable number.

21951988604 is an abundant number, since it is smaller than the sum of its proper divisors (25771182724).

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

21951988604 is a wasteful number, since it uses less digits than its factorization.

21951988604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563754 (or 563752 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 53.

The spelling of 21951988604 in words is "twenty-one billion, nine hundred fifty-one million, nine hundred eighty-eight thousand, six hundred four".