21101221120 has 72 divisors (see below), whose sum is σ = 57764617344. Its totient is φ = 7234701312.

The previous prime is 21101221103. The next prime is 21101221129. The reversal of 21101221120 is 2112210112.

It is a self number, because there is not a number n which added to its sum of digits gives 21101221120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101221129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1168564 + ... + 1186483.

It is an arithmetic number, because the mean of its divisors is an integer number (802286352).

Almost surely, 2^21101221120 is an apocalyptic number.

21101221120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101221120 is an abundant number, since it is smaller than the sum of its proper divisors (36663396224).

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

21101221120 is an equidigital number, since it uses as much as digits as its factorization.

21101221120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2355075 (or 2355061 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21101221120 its reverse (2112210112), we get a palindrome (23213431232).

The spelling of 21101221120 in words is "twenty-one billion, one hundred one million, two hundred twenty-one thousand, one hundred twenty".