21202011020121 has 4 divisors (see below), whose sum is σ = 28269348026832. Its totient is φ = 14134674013412.

The previous prime is 21202011020119. The next prime is 21202011020167. The reversal of 21202011020121 is 12102011020212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21202011020121 - 2¹ = 21202011020119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21202011020121.

It is not an unprimeable number, because it can be changed into a prime (21202011020521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3533668503351 + ... + 3533668503356.

It is an arithmetic number, because the mean of its divisors is an integer number (7067337006708).

Almost surely, 2^{21202011020121} is an apocalyptic number.

It is an amenable number.

21202011020121 is a deficient number, since it is larger than the sum of its proper divisors (7067337006711).

21202011020121 is an equidigital number, since it uses as much as digits as its factorization.

21202011020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7067337006710.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21202011020121 its reverse (12102011020212), we get a palindrome (33304022040333).

Subtracting from 21202011020121 its reverse (12102011020212), we obtain a palindrome (9099999999909).

The spelling of 21202011020121 in words is "twenty-one trillion, two hundred two billion, eleven million, twenty thousand, one hundred twenty-one".