21204441052520 has 128 divisors (see below), whose sum is σ = 52981013952000. Its totient is φ = 7573256570880.

The previous prime is 21204441052519. The next prime is 21204441052537. The reversal of 21204441052520 is 2525014440212.

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, 6295586 + ... + 9057774.

It is an arithmetic number, because the mean of its divisors is an integer number (413914171500).

Almost surely, 2^{21204441052520} is an apocalyptic number.

21204441052520 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 21204441052520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26490506976000).

21204441052520 is an abundant number, since it is smaller than the sum of its proper divisors (31776572899480).

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

21204441052520 is a wasteful number, since it uses less digits than its factorization.

21204441052520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2762523 (or 2762519 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 32.

Adding to 21204441052520 its reverse (2525014440212), we get a palindrome (23729455492732).

The spelling of 21204441052520 in words is "twenty-one trillion, two hundred four billion, four hundred forty-one million, fifty-two thousand, five hundred twenty".