21937937520 has 320 divisors, whose sum is σ = 70990992000. Its totient is φ = 5601361920.

The previous prime is 21937937519. The next prime is 21937937531. The reversal of 21937937520 is 2573973912.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21937937520.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 147234406 + ... + 147234554.

It is an arithmetic number, because the mean of its divisors is an integer number (221846850).

Almost surely, 2^21937937520 is an apocalyptic number.

21937937520 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 21937937520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35495496000).

21937937520 is an abundant number, since it is smaller than the sum of its proper divisors (49053054480).

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

21937937520 is a wasteful number, since it uses less digits than its factorization.

21937937520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 714420, while the sum is 48.

The spelling of 21937937520 in words is "twenty-one billion, nine hundred thirty-seven million, nine hundred thirty-seven thousand, five hundred twenty".