311681597891 has 2 divisors, whose sum is σ = 311681597892. Its totient is φ = 311681597890.

The previous prime is 311681597833. The next prime is 311681597917. The reversal of 311681597891 is 198795186113.

It is a strong prime.

It is an emirp because it is prime and its reverse (198795186113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 311681597891 - 2⁶ = 311681597827 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 311681597891.

It is not a weakly prime, because it can be changed into another prime (311681587891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155840798945 + 155840798946.

It is an arithmetic number, because the mean of its divisors is an integer number (155840798946).

Almost surely, 2^311681597891 is an apocalyptic number.

311681597891 is a deficient number, since it is larger than the sum of its proper divisors (1).

311681597891 is an equidigital number, since it uses as much as digits as its factorization.

311681597891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 59.

The spelling of 311681597891 in words is "three hundred eleven billion, six hundred eighty-one million, five hundred ninety-seven thousand, eight hundred ninety-one".