21112321220 has 48 divisors (see below), whose sum is σ = 45827539968. Its totient is φ = 8161534080.

The previous prime is 21112321211. The next prime is 21112321259. The reversal of 21112321220 is 2212321112.

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, 446849 + ... + 491831.

It is an arithmetic number, because the mean of its divisors is an integer number (954740416).

Almost surely, 2^21112321220 is an apocalyptic number.

21112321220 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 21112321220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22913769984).

21112321220 is an abundant number, since it is smaller than the sum of its proper divisors (24715218748).

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

21112321220 is a wasteful number, since it uses less digits than its factorization.

21112321220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45780 (or 45778 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21112321220 its reverse (2212321112), we get a palindrome (23324642332).

The spelling of 21112321220 in words is "twenty-one billion, one hundred twelve million, three hundred twenty-one thousand, two hundred twenty".