21522444320 has 96 divisors (see below), whose sum is σ = 54953059392. Its totient is φ = 7918451712.

The previous prime is 21522444299. The next prime is 21522444341. The reversal of 21522444320 is 2344422512.

It is an interprime number because it is at equal distance from previous prime (21522444299) and next prime (21522444341).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 570359 + ... + 606921.

It is an arithmetic number, because the mean of its divisors is an integer number (572427702).

Almost surely, 2^21522444320 is an apocalyptic number.

21522444320 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 21522444320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27476529696).

21522444320 is an abundant number, since it is smaller than the sum of its proper divisors (33430615072).

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

21522444320 is a wasteful number, since it uses less digits than its factorization.

21522444320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36874 (or 36866 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 29.

Adding to 21522444320 its reverse (2344422512), we get a palindrome (23866866832).

The spelling of 21522444320 in words is "twenty-one billion, five hundred twenty-two million, four hundred forty-four thousand, three hundred twenty".