21002000202121 has 32 divisors (see below), whose sum is σ = 21562494347520. Its totient is φ = 20448197812224.

The previous prime is 21002000202101. The next prime is 21002000202181. The reversal of 21002000202121 is 12120200020012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21002000202121 - 2³⁷ = 20864561248649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21002000202101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13052827165 + ... + 13052828773.

It is an arithmetic number, because the mean of its divisors is an integer number (673827948360).

Almost surely, 2^{21002000202121} is an apocalyptic number.

It is an amenable number.

21002000202121 is a deficient number, since it is larger than the sum of its proper divisors (560494145399).

21002000202121 is a wasteful number, since it uses less digits than its factorization.

21002000202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4225.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21002000202121 its reverse (12120200020012), we get a palindrome (33122200222133).

The spelling of 21002000202121 in words is "twenty-one trillion, two billion, two hundred two thousand, one hundred twenty-one".