1311302561 has 2 divisors, whose sum is σ = 1311302562. Its totient is φ = 1311302560.

The previous prime is 1311302527. The next prime is 1311302569. The reversal of 1311302561 is 1652031131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1306099600 + 5202961 = 36140^2 + 2281^2 .

It is an emirp because it is prime and its reverse (1652031131) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311302561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1311302569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655651280 + 655651281.

It is an arithmetic number, because the mean of its divisors is an integer number (655651281).

Almost surely, 2^1311302561 is an apocalyptic number.

It is an amenable number.

1311302561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311302561 is an equidigital number, since it uses as much as digits as its factorization.

1311302561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1311302561 is about 36211.9118661249. The cubic root of 1311302561 is about 1094.5467181369.

Adding to 1311302561 its reverse (1652031131), we get a palindrome (2963333692).

The spelling of 1311302561 in words is "one billion, three hundred eleven million, three hundred two thousand, five hundred sixty-one".