18618813 has 6 divisors (see below), whose sum is σ = 26893854. Its totient is φ = 12412536.

The previous prime is 18618811. The next prime is 18618857. The reversal of 18618813 is 31881681.

It can be written as a sum of positive squares in only one way, i.e., 17614809 + 1004004 = 4197^2 + 1002^2 .

It is not a de Polignac number, because 18618813 - 2¹ = 18618811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18618811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1034370 + ... + 1034387.

It is an arithmetic number, because the mean of its divisors is an integer number (4482309).

Almost surely, 2^18618813 is an apocalyptic number.

It is an amenable number.

18618813 is a deficient number, since it is larger than the sum of its proper divisors (8275041).

18618813 is a wasteful number, since it uses less digits than its factorization.

18618813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2068763 (or 2068760 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 18618813 is about 4314.9522592956. The cubic root of 18618813 is about 265.0436050234.

The spelling of 18618813 in words is "eighteen million, six hundred eighteen thousand, eight hundred thirteen".