221222100221 has 4 divisors (see below), whose sum is σ = 226617761244. Its totient is φ = 215826439200.

The previous prime is 221222100173. The next prime is 221222100299. The reversal of 221222100221 is 122001222122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15002575225 + 206219524996 = 122485^2 + 454114^2 .

It is a cyclic number.

It is not a de Polignac number, because 221222100221 - 2⁶ = 221222100157 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 221222100221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221222100821) 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 3 ways as a sum of consecutive naturals, for example, 2697830450 + ... + 2697830531.

It is an arithmetic number, because the mean of its divisors is an integer number (56654440311).

Almost surely, 2^221222100221 is an apocalyptic number.

It is an amenable number.

221222100221 is a deficient number, since it is larger than the sum of its proper divisors (5395661023).

221222100221 is an equidigital number, since it uses as much as digits as its factorization.

221222100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5395661022.

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

Adding to 221222100221 its reverse (122001222122), we get a palindrome (343223322343).

The spelling of 221222100221 in words is "two hundred twenty-one billion, two hundred twenty-two million, one hundred thousand, two hundred twenty-one".