21513704960 has 320 divisors, whose sum is σ = 58465186560. Its totient is φ = 7524679680.

The previous prime is 21513704929. The next prime is 21513704963. The reversal of 21513704960 is 6940731512.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×21513704960² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513704963) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131985839 + ... + 131986001.

It is an arithmetic number, because the mean of its divisors is an integer number (182703708).

Almost surely, 2^21513704960 is an apocalyptic number.

21513704960 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 21513704960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29232593280).

21513704960 is an abundant number, since it is smaller than the sum of its proper divisors (36951481600).

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

21513704960 is a wasteful number, since it uses less digits than its factorization.

21513704960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The spelling of 21513704960 in words is "twenty-one billion, five hundred thirteen million, seven hundred four thousand, nine hundred sixty".