21937635720 has 768 divisors, whose sum is σ = 101387220480. Its totient is φ = 3959193600.

The previous prime is 21937635691. The next prime is 21937635743. The reversal of 21937635720 is 2753673912.

21937635720 is a `hidden beast` number, since 2 + 1 + 9 + 3 + 7 + 635 + 7 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 6124330 + ... + 6127910.

It is an arithmetic number, because the mean of its divisors is an integer number (132014610).

Almost surely, 2^21937635720 is an apocalyptic number.

21937635720 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 21937635720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50693610240).

21937635720 is an abundant number, since it is smaller than the sum of its proper divisors (79449584760).

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

21937635720 is a wasteful number, since it uses less digits than its factorization.

21937635720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3646 (or 3639 counting only the distinct ones).

The product of its (nonzero) digits is 476280, while the sum is 45.

The spelling of 21937635720 in words is "twenty-one billion, nine hundred thirty-seven million, six hundred thirty-five thousand, seven hundred twenty".