21324625920 has 768 divisors, whose sum is σ = 86682960000. Its totient is φ = 4926210048.

The previous prime is 21324625913. The next prime is 21324625939. The reversal of 21324625920 is 2952642312.

21324625920 is a `hidden beast` number, since 2 + 1 + 3 + 2 + 4 + 62 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 61101906 + ... + 61102254.

Almost surely, 2^21324625920 is an apocalyptic number.

21324625920 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 21324625920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43341480000).

21324625920 is an abundant number, since it is smaller than the sum of its proper divisors (65358334080).

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

21324625920 is a wasteful number, since it uses less digits than its factorization.

21324625920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 21324625920 in words is "twenty-one billion, three hundred twenty-four million, six hundred twenty-five thousand, nine hundred twenty".