21111102020 has 12 divisors (see below), whose sum is σ = 44333314284. Its totient is φ = 8444440800.

The previous prime is 21111102017. The next prime is 21111102031. The reversal of 21111102020 is 2020111112.

It can be written as a sum of positive squares in 2 ways, for example, as 14481234244 + 6629867776 = 120338^2 + 81424^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21111101992 and 21111102010.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 527777531 + ... + 527777570.

It is an arithmetic number, because the mean of its divisors is an integer number (3694442857).

Almost surely, 2^21111102020 is an apocalyptic number.

21111102020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111102020 is an abundant number, since it is smaller than the sum of its proper divisors (23222212264).

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

21111102020 is a wasteful number, since it uses less digits than its factorization.

21111102020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1055555110 (or 1055555108 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21111102020 its reverse (2020111112), we get a palindrome (23131213132).

The spelling of 21111102020 in words is "twenty-one billion, one hundred eleven million, one hundred two thousand, twenty".