21903446464 has 56 divisors (see below), whose sum is σ = 44206119360. Its totient is φ = 10766106624.

The previous prime is 21903446447. The next prime is 21903446471. The reversal of 21903446464 is 46464430912.

It is a self number, because there is not a number n which added to its sum of digits gives 21903446464.

It is a congruent number.

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, 1168752 + ... + 1187344.

Almost surely, 2^21903446464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21903446464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22103059680).

21903446464 is an abundant number, since it is smaller than the sum of its proper divisors (22302672896).

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

21903446464 is a wasteful number, since it uses less digits than its factorization.

21903446464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18917 (or 18907 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 43.

The spelling of 21903446464 in words is "twenty-one billion, nine hundred three million, four hundred forty-six thousand, four hundred sixty-four".