21207889600 has 168 divisors, whose sum is σ = 53836616736. Its totient is φ = 8217600000.

The previous prime is 21207889553. The next prime is 21207889643. The reversal of 21207889600 is 698870212.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9904530 + ... + 9906670.

It is an arithmetic number, because the mean of its divisors is an integer number (320456052).

Almost surely, 2^21207889600 is an apocalyptic number.

21207889600 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 21207889600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26918308368).

21207889600 is an abundant number, since it is smaller than the sum of its proper divisors (32628727136).

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

21207889600 is a wasteful number, since it uses less digits than its factorization.

21207889600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2355 (or 2340 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 21207889600 in words is "twenty-one billion, two hundred seven million, eight hundred eighty-nine thousand, six hundred".