21002002120100 has 36 divisors (see below), whose sum is σ = 45581196239124. Its totient is φ = 8399537873280.

The previous prime is 21002002120063. The next prime is 21002002120207. The reversal of 21002002120100 is 102120020012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 960192251236 + 20041809868864 = 979894^2 + 4476808^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15118559 + ... + 16449158.

Almost surely, 2^{21002002120100} is an apocalyptic number.

21002002120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002002120100 is an abundant number, since it is smaller than the sum of its proper divisors (24579194119024).

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

21002002120100 is a wasteful number, since it uses less digits than its factorization.

21002002120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31574384 (or 31574377 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21002002120100 its reverse (102120020012), we get a palindrome (21104122140112).

The spelling of 21002002120100 in words is "twenty-one trillion, two billion, two million, one hundred twenty thousand, one hundred".