21360997888 has 160 divisors (see below), whose sum is σ = 45678504960. Its totient is φ = 9963233280.

The previous prime is 21360997883. The next prime is 21360997901. The reversal of 21360997888 is 88879906312.

It is a super-2 number, since 2×21360997888² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21360997883) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 56361283 + ... + 56361661.

It is an arithmetic number, because the mean of its divisors is an integer number (285490656).

Almost surely, 2^21360997888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21360997888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22839252480).

21360997888 is an abundant number, since it is smaller than the sum of its proper divisors (24317507072).

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

21360997888 is an equidigital number, since it uses as much as digits as its factorization.

21360997888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548 (or 532 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 61.

The spelling of 21360997888 in words is "twenty-one billion, three hundred sixty million, nine hundred ninety-seven thousand, eight hundred eighty-eight".