221112211121 has 2 divisors, whose sum is σ = 221112211122. Its totient is φ = 221112211120.

The previous prime is 221112211109. The next prime is 221112211193. The reversal of 221112211121 is 121112211122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 219177530896 + 1934680225 = 468164^2 + 43985^2 .

It is a cyclic number.

It is not a de Polignac number, because 221112211121 - 2⁶ = 221112211057 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 221112211121.

It is not a weakly prime, because it can be changed into another prime (221112211321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110556105560 + 110556105561.

It is an arithmetic number, because the mean of its divisors is an integer number (110556105561).

Almost surely, 2^221112211121 is an apocalyptic number.

It is an amenable number.

221112211121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221112211121 is an equidigital number, since it uses as much as digits as its factorization.

221112211121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 17.

Adding to 221112211121 its reverse (121112211122), we get a palindrome (342224422243).

Subtracting from 221112211121 its reverse (121112211122), we obtain a palindrome (99999999999).

The spelling of 221112211121 in words is "two hundred twenty-one billion, one hundred twelve million, two hundred eleven thousand, one hundred twenty-one".