1311523217 has 2 divisors, whose sum is σ = 1311523218. Its totient is φ = 1311523216.

The previous prime is 1311523189. The next prime is 1311523229. The reversal of 1311523217 is 7123251131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1163560321 + 147962896 = 34111^2 + 12164^2 .

It is an emirp because it is prime and its reverse (7123251131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1311523217 - 2⁶ = 1311523153 is a prime.

It is not a weakly prime, because it can be changed into another prime (1311523817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655761608 + 655761609.

It is an arithmetic number, because the mean of its divisors is an integer number (655761609).

Almost surely, 2^1311523217 is an apocalyptic number.

It is an amenable number.

1311523217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311523217 is an equidigital number, since it uses as much as digits as its factorization.

1311523217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 26.

The square root of 1311523217 is about 36214.9584702233. The cubic root of 1311523217 is about 1094.6081086866.

Adding to 1311523217 its reverse (7123251131), we get a palindrome (8434774348).

The spelling of 1311523217 in words is "one billion, three hundred eleven million, five hundred twenty-three thousand, two hundred seventeen".