1311531138817 has 2 divisors, whose sum is σ = 1311531138818. Its totient is φ = 1311531138816.

The previous prime is 1311531138763. The next prime is 1311531138913. The reversal of 1311531138817 is 7188311351131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 915406919361 + 396124219456 = 956769^2 + 629384^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311531138817 - 2²⁷ = 1311396921089 is a prime.

It is a super-2 number, since 2×1311531138817² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1311531138917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655765569408 + 655765569409.

It is an arithmetic number, because the mean of its divisors is an integer number (655765569409).

Almost surely, 2^{1311531138817} is an apocalyptic number.

It is an amenable number.

1311531138817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311531138817 is an equidigital number, since it uses as much as digits as its factorization.

1311531138817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 43.

Adding to 1311531138817 its reverse (7188311351131), we get a palindrome (8499842489948).

The spelling of 1311531138817 in words is "one trillion, three hundred eleven billion, five hundred thirty-one million, one hundred thirty-eight thousand, eight hundred seventeen".