21221000002221 has 32 divisors (see below), whose sum is σ = 30430349568000. Its totient is φ = 13113225223488.

The previous prime is 21221000002217. The next prime is 21221000002249. The reversal of 21221000002221 is 12220000012212.

It is not a de Polignac number, because 21221000002221 - 2² = 21221000002217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221000002221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221000002271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8698881 + ... + 10867958.

It is an arithmetic number, because the mean of its divisors is an integer number (950948424000).

Almost surely, 2^{21221000002221} is an apocalyptic number.

It is an amenable number.

21221000002221 is a deficient number, since it is larger than the sum of its proper divisors (9209349565779).

21221000002221 is a wasteful number, since it uses less digits than its factorization.

21221000002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19567273.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21221000002221 its reverse (12220000012212), we get a palindrome (33441000014433).

Subtracting from 21221000002221 its reverse (12220000012212), we obtain a palindrome (9000999990009).

The spelling of 21221000002221 in words is "twenty-one trillion, two hundred twenty-one billion, two thousand, two hundred twenty-one".