918181813 has 2 divisors, whose sum is σ = 918181814. Its totient is φ = 918181812.

The previous prime is 918181793. The next prime is 918181837. The reversal of 918181813 is 318181819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 852523204 + 65658609 = 29198^2 + 8103^2 .

It is an emirp because it is prime and its reverse (318181819) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-918181813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (918181013) 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, 459090906 + 459090907.

It is an arithmetic number, because the mean of its divisors is an integer number (459090907).

Almost surely, 2^918181813 is an apocalyptic number.

It is an amenable number.

918181813 is a deficient number, since it is larger than the sum of its proper divisors (1).

918181813 is an equidigital number, since it uses as much as digits as its factorization.

918181813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 40.

The square root of 918181813 is about 30301.5150281302. The cubic root of 918181813 is about 971.9476977536.

The spelling of 918181813 in words is "nine hundred eighteen million, one hundred eighty-one thousand, eight hundred thirteen".