21525513600 has 192 divisors, whose sum is σ = 71004986640. Its totient is φ = 5731614720.

The previous prime is 21525513593. The next prime is 21525513601. The reversal of 21525513600 is 631552512.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525513601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8994004 + ... + 8996396.

Almost surely, 2^21525513600 is an apocalyptic number.

21525513600 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 21525513600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35502493320).

21525513600 is an abundant number, since it is smaller than the sum of its proper divisors (49479473040).

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

21525513600 is a wasteful number, since it uses less digits than its factorization.

21525513600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3357 (or 3340 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21525513600 in words is "twenty-one billion, five hundred twenty-five million, five hundred thirteen thousand, six hundred".