21111122100020 has 24 divisors (see below), whose sum is σ = 44615734482984. Its totient is φ = 8390662540416.

The previous prime is 21111122099983. The next prime is 21111122100031. The reversal of 21111122100020 is 2000122111112.

It can be written as a sum of positive squares in 4 ways, for example, as 25190768656 + 21085931331364 = 158716^2 + 4591942^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21111122099968 and 21111122100004.

It is a congruent number.

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, 3361640507 + ... + 3361646786.

It is an arithmetic number, because the mean of its divisors is an integer number (1858988936791).

Almost surely, 2^{21111122100020} is an apocalyptic number.

21111122100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111122100020 is an abundant number, since it is smaller than the sum of its proper divisors (23504612382964).

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

21111122100020 is a wasteful number, since it uses less digits than its factorization.

21111122100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6723287459 (or 6723287457 counting only the distinct ones).

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

Adding to 21111122100020 its reverse (2000122111112), we get a palindrome (23111244211132).

The spelling of 21111122100020 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-two million, one hundred thousand, twenty".