318986813 has 2 divisors, whose sum is σ = 318986814. Its totient is φ = 318986812.

The previous prime is 318986803. The next prime is 318986821. The reversal of 318986813 is 318689813.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 298529284 + 20457529 = 17278^2 + 4523^2 .

It is a cyclic number.

It is not a de Polignac number, because 318986813 - 2⁴ = 318986797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (318986803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159493406 + 159493407.

It is an arithmetic number, because the mean of its divisors is an integer number (159493407).

Almost surely, 2^318986813 is an apocalyptic number.

It is an amenable number.

318986813 is a deficient number, since it is larger than the sum of its proper divisors (1).

318986813 is an equidigital number, since it uses as much as digits as its factorization.

318986813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 47.

The square root of 318986813 is about 17860.2019305494. The cubic root of 318986813 is about 683.2677298643.

The spelling of 318986813 in words is "three hundred eighteen million, nine hundred eighty-six thousand, eight hundred thirteen".