21222200100221 has 4 divisors (see below), whose sum is σ = 21222247018752. Its totient is φ = 21222153181692.

The previous prime is 21222200100203. The next prime is 21222200100251. The reversal of 21222200100221 is 12200100222212.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-21222200100221 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 21222200100221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222200100251) 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, 22774115 + ... + 23687648.

It is an arithmetic number, because the mean of its divisors is an integer number (5305561754688).

Almost surely, 2^{21222200100221} is an apocalyptic number.

It is an amenable number.

21222200100221 is a deficient number, since it is larger than the sum of its proper divisors (46918531).

21222200100221 is an equidigital number, since it uses as much as digits as its factorization.

21222200100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46918530.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21222200100221 its reverse (12200100222212), we get a palindrome (33422300322433).

The spelling of 21222200100221 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred million, one hundred thousand, two hundred twenty-one".