21211102221021 has 24 divisors (see below), whose sum is σ = 30749380566840. Its totient is φ = 14089454668800.

The previous prime is 21211102220947. The next prime is 21211102221061. The reversal of 21211102221021 is 12012220111212.

It can be written as a sum of positive squares in 4 ways, for example, as 39269367225 + 21171832853796 = 198165^2 + 4601286^2 .

It is not a de Polignac number, because 21211102221021 - 2⁹ = 21211102220509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211102220985 and 21211102221003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211102221061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37963675 + ... + 38518343.

It is an arithmetic number, because the mean of its divisors is an integer number (1281224190285).

Almost surely, 2^{21211102221021} is an apocalyptic number.

It is an amenable number.

21211102221021 is a deficient number, since it is larger than the sum of its proper divisors (9538278345819).

21211102221021 is a wasteful number, since it uses less digits than its factorization.

21211102221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570077 (or 570074 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21211102221021 its reverse (12012220111212), we get a palindrome (33223322332233).

The spelling of 21211102221021 in words is "twenty-one trillion, two hundred eleven billion, one hundred two million, two hundred twenty-one thousand, twenty-one".