21002222102221 has 8 divisors (see below), whose sum is σ = 21731377984920. Its totient is φ = 20273395641408.

The previous prime is 21002222102149. The next prime is 21002222102227. The reversal of 21002222102221 is 12220122220012.

It can be written as a sum of positive squares in 4 ways, for example, as 3257613472996 + 17744608629225 = 1804886^2 + 4212435^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21002222102221 - 2⁷ = 21002222102093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002222102227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82225746 + ... + 82480771.

It is an arithmetic number, because the mean of its divisors is an integer number (2716422248115).

Almost surely, 2^{21002222102221} is an apocalyptic number.

It is an amenable number.

21002222102221 is a deficient number, since it is larger than the sum of its proper divisors (729155882699).

21002222102221 is a wasteful number, since it uses less digits than its factorization.

21002222102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164710943.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21002222102221 its reverse (12220122220012), we get a palindrome (33222344322233).

The spelling of 21002222102221 in words is "twenty-one trillion, two billion, two hundred twenty-two million, one hundred two thousand, two hundred twenty-one".