21623537320 has 288 divisors, whose sum is σ = 63111825000. Its totient is φ = 6642155520.

The previous prime is 21623537303. The next prime is 21623537357. The reversal of 21623537320 is 2373532612.

It can be written as a sum of positive squares in 4 ways, for example, as 17094516516 + 4529020804 = 130746^2 + 67298^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 17312056 + ... + 17313304.

Almost surely, 2^21623537320 is an apocalyptic number.

21623537320 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 21623537320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31555912500).

21623537320 is an abundant number, since it is smaller than the sum of its proper divisors (41488287680).

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

21623537320 is a wasteful number, since it uses less digits than its factorization.

21623537320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369 (or 1347 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 34.

The spelling of 21623537320 in words is "twenty-one billion, six hundred twenty-three million, five hundred thirty-seven thousand, three hundred twenty".