21210020021100 has 36 divisors (see below), whose sum is σ = 61367657928584. Its totient is φ = 5656005338880.

The previous prime is 21210020021093. The next prime is 21210020021143. The reversal of 21210020021100 is 112002001212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35350033069 + ... + 35350033668.

Almost surely, 2^{21210020021100} is an apocalyptic number.

21210020021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210020021100 is an abundant number, since it is smaller than the sum of its proper divisors (40157637907484).

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

21210020021100 is a wasteful number, since it uses less digits than its factorization.

21210020021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70700066754 (or 70700066747 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21210020021100 its reverse (112002001212), we get a palindrome (21322022022312).

The spelling of 21210020021100 in words is "twenty-one trillion, two hundred ten billion, twenty million, twenty-one thousand, one hundred".