21903521604 has 24 divisors (see below), whose sum is σ = 51414259008. Its totient is φ = 7257453600.

The previous prime is 21903521573. The next prime is 21903521623. The reversal of 21903521604 is 40612530912.

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, 5462947 + ... + 5466954.

It is an arithmetic number, because the mean of its divisors is an integer number (2142260792).

Almost surely, 2^21903521604 is an apocalyptic number.

It is an amenable number.

21903521604 is an abundant number, since it is smaller than the sum of its proper divisors (29510737404).

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

21903521604 is a wasteful number, since it uses less digits than its factorization.

21903521604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10930075 (or 10930073 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The spelling of 21903521604 in words is "twenty-one billion, nine hundred three million, five hundred twenty-one thousand, six hundred four".