21604520000 has 560 divisors, whose sum is σ = 67034542080. Its totient is φ = 6739200000.

The previous prime is 21604519997. The next prime is 21604520029. The reversal of 21604520000 is 2540612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 164919935 + ... + 164920065.

Almost surely, 2^21604520000 is an apocalyptic number.

21604520000 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 21604520000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33517271040).

21604520000 is an abundant number, since it is smaller than the sum of its proper divisors (45430022080).

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

21604520000 is a wasteful number, since it uses less digits than its factorization.

21604520000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The spelling of 21604520000 in words is "twenty-one billion, six hundred four million, five hundred twenty thousand".