21444500220 has 192 divisors, whose sum is σ = 71053355520. Its totient is φ = 4763980800.

The previous prime is 21444500191. The next prime is 21444500239. The reversal of 21444500220 is 2200544412.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1183630 + ... + 1201610.

It is an arithmetic number, because the mean of its divisors is an integer number (370069560).

Almost surely, 2^21444500220 is an apocalyptic number.

21444500220 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 21444500220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35526677760).

21444500220 is an abundant number, since it is smaller than the sum of its proper divisors (49608855300).

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

21444500220 is a wasteful number, since it uses less digits than its factorization.

21444500220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18156 (or 18154 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 24.

The spelling of 21444500220 in words is "twenty-one billion, four hundred forty-four million, five hundred thousand, two hundred twenty".