21210222211021 has 4 divisors (see below), whose sum is σ = 21210286088992. Its totient is φ = 21210158333052.

The previous prime is 21210222211001. The next prime is 21210222211063. The reversal of 21210222211021 is 12011222201212.

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 21210222211021 - 2²⁵ = 21210188656589 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 21210222211021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210222211001) 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, 31438305 + ... + 32105878.

It is an arithmetic number, because the mean of its divisors is an integer number (5302571522248).

Almost surely, 2^{21210222211021} is an apocalyptic number.

It is an amenable number.

21210222211021 is a deficient number, since it is larger than the sum of its proper divisors (63877971).

21210222211021 is an equidigital number, since it uses as much as digits as its factorization.

21210222211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63877970.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21210222211021 its reverse (12011222201212), we get a palindrome (33221444412233).

The spelling of 21210222211021 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty-two million, two hundred eleven thousand, twenty-one".