18640318 has 4 divisors (see below), whose sum is σ = 27960480. Its totient is φ = 9320158.

The previous prime is 18640309. The next prime is 18640333. The reversal of 18640318 is 81304681.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×18640318² = 694922910282248, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 18640318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4660078 + ... + 4660081.

It is an arithmetic number, because the mean of its divisors is an integer number (6990120).

Almost surely, 2^18640318 is an apocalyptic number.

18640318 is a deficient number, since it is larger than the sum of its proper divisors (9320162).

18640318 is an equidigital number, since it uses as much as digits as its factorization.

18640318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9320161.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 18640318 is about 4317.4434564914. The cubic root of 18640318 is about 265.1456088353.

Adding to 18640318 its reverse (81304681), we get a palindrome (99944999).

It can be divided in two parts, 186 and 40318, that added together give a palindrome (40504).

The spelling of 18640318 in words is "eighteen million, six hundred forty thousand, three hundred eighteen".