1311225217 has 2 divisors, whose sum is σ = 1311225218. Its totient is φ = 1311225216.

The previous prime is 1311225191. The next prime is 1311225233. The reversal of 1311225217 is 7125221131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 730945296 + 580279921 = 27036^2 + 24089^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311225217 - 2²³ = 1302836609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311225191 and 1311225200.

It is not a weakly prime, because it can be changed into another prime (1311225917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655612608 + 655612609.

It is an arithmetic number, because the mean of its divisors is an integer number (655612609).

Almost surely, 2^1311225217 is an apocalyptic number.

It is an amenable number.

1311225217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311225217 is an equidigital number, since it uses as much as digits as its factorization.

1311225217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 25.

The square root of 1311225217 is about 36210.8439144961. The cubic root of 1311225217 is about 1094.5251979863.

Adding to 1311225217 its reverse (7125221131), we get a palindrome (8436446348).

The spelling of 1311225217 in words is "one billion, three hundred eleven million, two hundred twenty-five thousand, two hundred seventeen".