221100231221 has 2 divisors, whose sum is σ = 221100231222. Its totient is φ = 221100231220.

The previous prime is 221100231193. The next prime is 221100231227. The reversal of 221100231221 is 122132001122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128422606321 + 92677624900 = 358361^2 + 304430^2 .

It is a cyclic number.

It is not a de Polignac number, because 221100231221 - 2²⁶ = 221033122357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221100231221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221100231227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110550115610 + 110550115611.

It is an arithmetic number, because the mean of its divisors is an integer number (110550115611).

Almost surely, 2^221100231221 is an apocalyptic number.

It is an amenable number.

221100231221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221100231221 is an equidigital number, since it uses as much as digits as its factorization.

221100231221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 221100231221 its reverse (122132001122), we get a palindrome (343232232343).

The spelling of 221100231221 in words is "two hundred twenty-one billion, one hundred million, two hundred thirty-one thousand, two hundred twenty-one".