21111200012020 has 24 divisors (see below), whose sum is σ = 44333607057768. Its totient is φ = 8444463427200.

The previous prime is 21111200011879. The next prime is 21111200012041. The reversal of 21111200012020 is 2021000211112.

It can be written as a sum of positive squares in 4 ways, for example, as 2492268430864 + 18618931581156 = 1578692^2 + 4314966^2 .

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, 17457790 + ... + 18627850.

It is an arithmetic number, because the mean of its divisors is an integer number (1847233627407).

Almost surely, 2^{21111200012020} is an apocalyptic number.

21111200012020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111200012020 is an abundant number, since it is smaller than the sum of its proper divisors (23222407045748).

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

21111200012020 is a wasteful number, since it uses less digits than its factorization.

21111200012020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2072211 (or 2072209 counting only the distinct ones).

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

Adding to 21111200012020 its reverse (2021000211112), we get a palindrome (23132200223132).

The spelling of 21111200012020 in words is "twenty-one trillion, one hundred eleven billion, two hundred million, twelve thousand, twenty".