318689257 has 2 divisors, whose sum is σ = 318689258. Its totient is φ = 318689256.

The previous prime is 318689249. The next prime is 318689279. The reversal of 318689257 is 752986813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 313325401 + 5363856 = 17701^2 + 2316^2 .

It is a cyclic number.

It is not a de Polignac number, because 318689257 - 2³ = 318689249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 318689257.

It is not a weakly prime, because it can be changed into another prime (318689237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159344628 + 159344629.

It is an arithmetic number, because the mean of its divisors is an integer number (159344629).

Almost surely, 2^318689257 is an apocalyptic number.

It is an amenable number.

318689257 is a deficient number, since it is larger than the sum of its proper divisors (1).

318689257 is an equidigital number, since it uses as much as digits as its factorization.

318689257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 49.

The square root of 318689257 is about 17851.8698460413. The cubic root of 318689257 is about 683.0552094150.

The spelling of 318689257 in words is "three hundred eighteen million, six hundred eighty-nine thousand, two hundred fifty-seven".