1331312557 has 2 divisors, whose sum is σ = 1331312558. Its totient is φ = 1331312556.

The previous prime is 1331312531. The next prime is 1331312569. The reversal of 1331312557 is 7552131331.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1314715081 + 16597476 = 36259^2 + 4074^2 .

It is an emirp because it is prime and its reverse (7552131331) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331312557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331312357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665656278 + 665656279.

It is an arithmetic number, because the mean of its divisors is an integer number (665656279).

Almost surely, 2^1331312557 is an apocalyptic number.

It is an amenable number.

1331312557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331312557 is an equidigital number, since it uses as much as digits as its factorization.

1331312557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9450, while the sum is 31.

The square root of 1331312557 is about 36487.1560552477. The cubic root of 1331312557 is about 1100.0860971177.

Adding to 1331312557 its reverse (7552131331), we get a palindrome (8883443888).

The spelling of 1331312557 in words is "one billion, three hundred thirty-one million, three hundred twelve thousand, five hundred fifty-seven".