16818385 has 4 divisors (see below), whose sum is σ = 20182068. Its totient is φ = 13454704.

The previous prime is 16818383. The next prime is 16818391. The reversal of 16818385 is 58381861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58381861 = 1297 ⋅45013.

It can be written as a sum of positive squares in 2 ways, for example, as 13373649 + 3444736 = 3657^2 + 1856^2 .

It is a cyclic number.

It is not a de Polignac number, because 16818385 - 2¹ = 16818383 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16818383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1681834 + ... + 1681843.

It is an arithmetic number, because the mean of its divisors is an integer number (5045517).

Almost surely, 2^16818385 is an apocalyptic number.

It is an amenable number.

16818385 is a deficient number, since it is larger than the sum of its proper divisors (3363683).

16818385 is an equidigital number, since it uses as much as digits as its factorization.

16818385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3363682.

The product of its digits is 46080, while the sum is 40.

The square root of 16818385 is about 4101.0224334914. The cubic root of 16818385 is about 256.2092253187.

The spelling of 16818385 in words is "sixteen million, eight hundred eighteen thousand, three hundred eighty-five".