1311222161 has 2 divisors, whose sum is σ = 1311222162. Its totient is φ = 1311222160.

The previous prime is 1311222119. The next prime is 1311222163. The reversal of 1311222161 is 1612221131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1280208400 + 31013761 = 35780^2 + 5569^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311222161 - 2²² = 1307027857 is a prime.

Together with 1311222163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1311222163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655611080 + 655611081.

It is an arithmetic number, because the mean of its divisors is an integer number (655611081).

Almost surely, 2^1311222161 is an apocalyptic number.

It is an amenable number.

1311222161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311222161 is an equidigital number, since it uses as much as digits as its factorization.

1311222161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 20.

The square root of 1311222161 is about 36210.8017171672. The cubic root of 1311222161 is about 1094.5243476692.

Adding to 1311222161 its reverse (1612221131), we get a palindrome (2923443292).

The spelling of 1311222161 in words is "one billion, three hundred eleven million, two hundred twenty-two thousand, one hundred sixty-one".