21037663920 has 960 divisors, whose sum is σ = 88458338304. Its totient is φ = 4087480320.

The previous prime is 21037663883. The next prime is 21037663963. The reversal of 21037663920 is 2936673012.

It is a Harshad number since it is a multiple of its sum of digits (39).

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 191 ways as a sum of consecutive naturals, for example, 109003344 + ... + 109003536.

Almost surely, 2^21037663920 is an apocalyptic number.

21037663920 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 21037663920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44229169152).

21037663920 is an abundant number, since it is smaller than the sum of its proper divisors (67420674384).

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

21037663920 is a wasteful number, since it uses less digits than its factorization.

21037663920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 39.

The spelling of 21037663920 in words is "twenty-one billion, thirty-seven million, six hundred sixty-three thousand, nine hundred twenty".