12212221261 has 2 divisors, whose sum is σ = 12212221262. Its totient is φ = 12212221260.

The previous prime is 12212221247. The next prime is 12212221267. The reversal of 12212221261 is 16212221221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10734203236 + 1478018025 = 103606^2 + 38445^2 .

It is a cyclic number.

It is not a de Polignac number, because 12212221261 - 2⁹ = 12212220749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12212221267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6106110630 + 6106110631.

It is an arithmetic number, because the mean of its divisors is an integer number (6106110631).

Almost surely, 2^12212221261 is an apocalyptic number.

It is an amenable number.

12212221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

12212221261 is an equidigital number, since it uses as much as digits as its factorization.

12212221261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 22.

Adding to 12212221261 its reverse (16212221221), we get a palindrome (28424442482).

The spelling of 12212221261 in words is "twelve billion, two hundred twelve million, two hundred twenty-one thousand, two hundred sixty-one".