21211202002120 has 64 divisors (see below), whose sum is σ = 51407502254640. Its totient is φ = 7830132710400.

The previous prime is 21211202002063. The next prime is 21211202002157. The reversal of 21211202002120 is 2120020211212.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 3892736892004 + 17318465110116 = 1973002^2 + 4161546^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21211202002094 and 21211202002103.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2010711 + ... + 6816550.

Almost surely, 2^{21211202002120} is an apocalyptic number.

21211202002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211202002120 is an abundant number, since it is smaller than the sum of its proper divisors (30196300252520).

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

21211202002120 is a wasteful number, since it uses less digits than its factorization.

21211202002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8831906 (or 8831902 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21211202002120 its reverse (2120020211212), we get a palindrome (23331222213332).

The spelling of 21211202002120 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, two thousand, one hundred twenty".