21202002220121 has 16 divisors (see below), whose sum is σ = 21538229650560. Its totient is φ = 20867053173120.

The previous prime is 21202002220093. The next prime is 21202002220171. The reversal of 21202002220121 is 12102220020212.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202002220121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21202002220121.

It is not an unprimeable number, because it can be changed into a prime (21202002220171) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 75196235 + ... + 75477663.

It is an arithmetic number, because the mean of its divisors is an integer number (1346139353160).

Almost surely, 2^{21202002220121} is an apocalyptic number.

It is an amenable number.

21202002220121 is a deficient number, since it is larger than the sum of its proper divisors (336227430439).

21202002220121 is a wasteful number, since it uses less digits than its factorization.

21202002220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283696.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21202002220121 its reverse (12102220020212), we get a palindrome (33304222240333).

The spelling of 21202002220121 in words is "twenty-one trillion, two hundred two billion, two million, two hundred twenty thousand, one hundred twenty-one".