318661591 has 2 divisors, whose sum is σ = 318661592. Its totient is φ = 318661590.

The previous prime is 318661579. The next prime is 318661601. The reversal of 318661591 is 195166813.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 318661591 - 2⁷ = 318661463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (318665591) 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, 159330795 + 159330796.

It is an arithmetic number, because the mean of its divisors is an integer number (159330796).

Almost surely, 2^318661591 is an apocalyptic number.

318661591 is a deficient number, since it is larger than the sum of its proper divisors (1).

318661591 is an equidigital number, since it uses as much as digits as its factorization.

318661591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 40.

The square root of 318661591 is about 17851.0949524112. The cubic root of 318661591 is about 683.0354430837.

The spelling of 318661591 in words is "three hundred eighteen million, six hundred sixty-one thousand, five hundred ninety-one".