21535643360 has 192 divisors, whose sum is σ = 66191053824. Its totient is φ = 6420480000.

The previous prime is 21535643359. The next prime is 21535643387. The reversal of 21535643360 is 6334653512.

It is a super-2 number, since 2×21535643360² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 245360 + ... + 321360.

It is an arithmetic number, because the mean of its divisors is an integer number (344745072).

Almost surely, 2^21535643360 is an apocalyptic number.

21535643360 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 21535643360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33095526912).

21535643360 is an abundant number, since it is smaller than the sum of its proper divisors (44655410464).

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

21535643360 is a wasteful number, since it uses less digits than its factorization.

21535643360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76057 (or 76049 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 38.

The spelling of 21535643360 in words is "twenty-one billion, five hundred thirty-five million, six hundred forty-three thousand, three hundred sixty".