21222004642521 has 8 divisors (see below), whose sum is σ = 28296034386144. Its totient is φ = 14147988996960.

The previous prime is 21222004642441. The next prime is 21222004642549. The reversal of 21222004642521 is 12524640022212.

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

It is not a de Polignac number, because 21222004642521 - 2²² = 21222000448217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21222004642121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 717126 + ... + 6554256.

It is an arithmetic number, because the mean of its divisors is an integer number (3537004298268).

Almost surely, 2^{21222004642521} is an apocalyptic number.

It is an amenable number.

21222004642521 is a deficient number, since it is larger than the sum of its proper divisors (7074029743623).

21222004642521 is a wasteful number, since it uses less digits than its factorization.

21222004642521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7049031.

The product of its (nonzero) digits is 30720, while the sum is 33.

Adding to 21222004642521 its reverse (12524640022212), we get a palindrome (33746644664733).

The spelling of 21222004642521 in words is "twenty-one trillion, two hundred twenty-two billion, four million, six hundred forty-two thousand, five hundred twenty-one".