1311251197 has 2 divisors, whose sum is σ = 1311251198. Its totient is φ = 1311251196.

The previous prime is 1311251131. The next prime is 1311251203. The reversal of 1311251197 is 7911521131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1300972761 + 10278436 = 36069^2 + 3206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311251197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311251297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655625598 + 655625599.

It is an arithmetic number, because the mean of its divisors is an integer number (655625599).

Almost surely, 2^1311251197 is an apocalyptic number.

It is an amenable number.

1311251197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311251197 is an equidigital number, since it uses as much as digits as its factorization.

1311251197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 31.

The square root of 1311251197 is about 36211.2026450379. The cubic root of 1311251197 is about 1094.5324267411.

The spelling of 1311251197 in words is "one billion, three hundred eleven million, two hundred fifty-one thousand, one hundred ninety-seven".