21002212100221 has 8 divisors (see below), whose sum is σ = 22911540221088. Its totient is φ = 19092889998000.

The previous prime is 21002212100173. The next prime is 21002212100269. The reversal of 21002212100221 is 12200121220012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21002212100173) and next prime (21002212100269).

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 21002212100221 - 2¹⁷ = 21002211969149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002212100195 and 21002212100204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002212100291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8949891 + ... + 11050111.

It is an arithmetic number, because the mean of its divisors is an integer number (2863942527636).

Almost surely, 2^{21002212100221} is an apocalyptic number.

It is an amenable number.

21002212100221 is a deficient number, since it is larger than the sum of its proper divisors (1909328120867).

21002212100221 is a wasteful number, since it uses less digits than its factorization.

21002212100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3009323.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21002212100221 its reverse (12200121220012), we get a palindrome (33202333320233).

The spelling of 21002212100221 in words is "twenty-one trillion, two billion, two hundred twelve million, one hundred thousand, two hundred twenty-one".