21897000960 has 384 divisors, whose sum is σ = 77441495040. Its totient is φ = 5253890048.

The previous prime is 21897000929. The next prime is 21897000973. The reversal of 21897000960 is 6900079812.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12010609 + ... + 12012431.

It is an arithmetic number, because the mean of its divisors is an integer number (201670560).

Almost surely, 2^21897000960 is an apocalyptic number.

21897000960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21897000960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38720747520).

21897000960 is an abundant number, since it is smaller than the sum of its proper divisors (55544494080).

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

21897000960 is a wasteful number, since it uses less digits than its factorization.

21897000960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1893 (or 1873 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The spelling of 21897000960 in words is "twenty-one billion, eight hundred ninety-seven million, nine hundred sixty", and thus it is an aban number.