21202212100121 has 4 divisors (see below), whose sum is σ = 22833151492452. Its totient is φ = 19571272707792.

The previous prime is 21202212100103. The next prime is 21202212100127. The reversal of 21202212100121 is 12100121220212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13599949971721 + 7602262128400 = 3687811^2 + 2757220^2 .

It is not a de Polignac number, because 21202212100121 - 2²² = 21202207905817 is a prime.

It is a super-3 number, since 3×21202212100121³ (a number of 41 digits) contains 333 as substring.

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 21202212100121.

It is not an unprimeable number, because it can be changed into a prime (21202212100127) 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, 815469696146 + ... + 815469696171.

It is an arithmetic number, because the mean of its divisors is an integer number (5708287873113).

Almost surely, 2^{21202212100121} is an apocalyptic number.

It is an amenable number.

21202212100121 is a deficient number, since it is larger than the sum of its proper divisors (1630939392331).

21202212100121 is a wasteful number, since it uses less digits than its factorization.

21202212100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630939392330.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21202212100121 its reverse (12100121220212), we get a palindrome (33302333320333).

The spelling of 21202212100121 in words is "twenty-one trillion, two hundred two billion, two hundred twelve million, one hundred thousand, one hundred twenty-one".