221266662121 has 2 divisors, whose sum is σ = 221266662122. Its totient is φ = 221266662120.

The previous prime is 221266662107. The next prime is 221266662161. The reversal of 221266662121 is 121266662122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121337968896 + 99928693225 = 348336^2 + 316115^2 .

It is a cyclic number.

It is not a de Polignac number, because 221266662121 - 2³⁷ = 83827708649 is a prime.

It is not a weakly prime, because it can be changed into another prime (221266662101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110633331060 + 110633331061.

It is an arithmetic number, because the mean of its divisors is an integer number (110633331061).

Almost surely, 2^221266662121 is an apocalyptic number.

It is an amenable number.

221266662121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221266662121 is an equidigital number, since it uses as much as digits as its factorization.

221266662121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 37.

Subtracting from 221266662121 its reverse (121266662122), we obtain a palindrome (99999999999).

The spelling of 221266662121 in words is "two hundred twenty-one billion, two hundred sixty-six million, six hundred sixty-two thousand, one hundred twenty-one".