21559508992 has 152 divisors (see below), whose sum is σ = 51002639360. Its totient is φ = 8918138880.

The previous prime is 21559508969. The next prime is 21559509007. The reversal of 21559508992 is 29980595512.

It is a happy number.

It is a super-2 number, since 2×21559508992² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56885059 + ... + 56885437.

It is an arithmetic number, because the mean of its divisors is an integer number (335543680).

Almost surely, 2^21559508992 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 21559508992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25501319680).

21559508992 is an abundant number, since it is smaller than the sum of its proper divisors (29443130368).

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

21559508992 is an frugal number, since it uses more digits than its factorization.

21559508992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 2916000, while the sum is 55.

The spelling of 21559508992 in words is "twenty-one billion, five hundred fifty-nine million, five hundred eight thousand, nine hundred ninety-two".