21100111201220 has 24 divisors (see below), whose sum is σ = 44520234638208. Its totient is φ = 8400044268000.

The previous prime is 21100111201207. The next prime is 21100111201261. The reversal of 21100111201220 is 2210211100112.

It is a super-2 number, since 2×21100111201220² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21100111201195 and 21100111201204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2500008956 + ... + 2500017395.

It is an arithmetic number, because the mean of its divisors is an integer number (1855009776592).

Almost surely, 2^{21100111201220} is an apocalyptic number.

21100111201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100111201220 is an abundant number, since it is smaller than the sum of its proper divisors (23420123436988).

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

21100111201220 is a wasteful number, since it uses less digits than its factorization.

21100111201220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5000026571 (or 5000026569 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21100111201220 its reverse (2210211100112), we get a palindrome (23310322301332).

The spelling of 21100111201220 in words is "twenty-one trillion, one hundred billion, one hundred eleven million, two hundred one thousand, two hundred twenty".