21021102112100 has 18 divisors (see below), whose sum is σ = 45615791583474. Its totient is φ = 8408440844800.

The previous prime is 21021102112099. The next prime is 21021102112111. The reversal of 21021102112100 is 121120112012.

It can be written as a sum of positive squares in 3 ways, for example, as 2045878236964 + 18975223875136 = 1430342^2 + 4356056^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105105510461 + ... + 105105510660.

Almost surely, 2^{21021102112100} is an apocalyptic number.

21021102112100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021102112100 is an abundant number, since it is smaller than the sum of its proper divisors (24594689471374).

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

21021102112100 is a wasteful number, since it uses less digits than its factorization.

21021102112100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210211021135 (or 210211021128 counting only the distinct ones).

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

Adding to 21021102112100 its reverse (121120112012), we get a palindrome (21142222224112).

The spelling of 21021102112100 in words is "twenty-one trillion, twenty-one billion, one hundred two million, one hundred twelve thousand, one hundred".