21202120202100 has 144 divisors (see below), whose sum is σ = 64956388525056. Its totient is φ = 5321064960000.

The previous prime is 21202120202071. The next prime is 21202120202113. The reversal of 21202120202100 is 120202120212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21202120202100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122930925 + ... + 123103275.

It is an arithmetic number, because the mean of its divisors is an integer number (451086031424).

Almost surely, 2^{21202120202100} is an apocalyptic number.

21202120202100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202120202100 is an abundant number, since it is smaller than the sum of its proper divisors (43754268322956).

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

21202120202100 is a wasteful number, since it uses less digits than its factorization.

21202120202100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196506 (or 196499 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21202120202100 its reverse (120202120212), we get a palindrome (21322322322312).

The spelling of 21202120202100 in words is "twenty-one trillion, two hundred two billion, one hundred twenty million, two hundred two thousand, one hundred".