18818505 has 12 divisors (see below), whose sum is σ = 32618820. Its totient is φ = 10036512.

The previous prime is 18818497. The next prime is 18818521. The reversal of 18818505 is 50581881.

It can be written as a sum of positive squares in 2 ways, for example, as 2585664 + 16232841 = 1608^2 + 4029^2 .

It is not a de Polignac number, because 18818505 - 2³ = 18818497 is a prime.

It is a super-2 number, since 2×18818505² = 708272260870050, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18818505.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 209050 + ... + 209139.

It is an arithmetic number, because the mean of its divisors is an integer number (2718235).

Almost surely, 2^18818505 is an apocalyptic number.

18818505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18818505 is a deficient number, since it is larger than the sum of its proper divisors (13800315).

18818505 is a wasteful number, since it uses less digits than its factorization.

18818505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418200 (or 418197 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 36.

The square root of 18818505 is about 4338.0300828832. The cubic root of 18818505 is about 265.9877931723.

The spelling of 18818505 in words is "eighteen million, eight hundred eighteen thousand, five hundred five".