31323316891 has 2 divisors, whose sum is σ = 31323316892. Its totient is φ = 31323316890.

The previous prime is 31323316883. The next prime is 31323316907. The reversal of 31323316891 is 19861332313.

It is a weak prime.

It is an emirp because it is prime and its reverse (19861332313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31323316891 - 2³ = 31323316883 is a prime.

It is not a weakly prime, because it can be changed into another prime (31323316091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15661658445 + 15661658446.

It is an arithmetic number, because the mean of its divisors is an integer number (15661658446).

Almost surely, 2^31323316891 is an apocalyptic number.

31323316891 is a deficient number, since it is larger than the sum of its proper divisors (1).

31323316891 is an equidigital number, since it uses as much as digits as its factorization.

31323316891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 40.

The spelling of 31323316891 in words is "thirty-one billion, three hundred twenty-three million, three hundred sixteen thousand, eight hundred ninety-one".