211111222261 has 2 divisors, whose sum is σ = 211111222262. Its totient is φ = 211111222260.

The previous prime is 211111222219. The next prime is 211111222339. The reversal of 211111222261 is 162222111112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 172648560100 + 38462662161 = 415510^2 + 196119^2 .

It is a cyclic number.

It is not a de Polignac number, because 211111222261 - 2³⁵ = 176751483893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211111222061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105555611130 + 105555611131.

It is an arithmetic number, because the mean of its divisors is an integer number (105555611131).

Almost surely, 2^211111222261 is an apocalyptic number.

It is an amenable number.

211111222261 is a deficient number, since it is larger than the sum of its proper divisors (1).

211111222261 is an equidigital number, since it uses as much as digits as its factorization.

211111222261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 22.

Adding to 211111222261 its reverse (162222111112), we get a palindrome (373333333373).

The spelling of 211111222261 in words is "two hundred eleven billion, one hundred eleven million, two hundred twenty-two thousand, two hundred sixty-one".