18218306 has 4 divisors (see below), whose sum is σ = 27327462. Its totient is φ = 9109152.

The previous prime is 18218287. The next prime is 18218311. The reversal of 18218306 is 60381281.

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

It can be written as a sum of positive squares in only one way, i.e., 16072081 + 2146225 = 4009^2 + 1465^2 .

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 as a sum of consecutive naturals, namely, 4554575 + ... + 4554578.

Almost surely, 2^18218306 is an apocalyptic number.

18218306 is a deficient number, since it is larger than the sum of its proper divisors (9109156).

18218306 is an equidigital number, since it uses as much as digits as its factorization.

18218306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9109155.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 18218306 is about 4268.2907586058. The cubic root of 18218306 is about 263.1293729467.

Adding to 18218306 its reverse (60381281), we get a palindrome (78599587).

The spelling of 18218306 in words is "eighteen million, two hundred eighteen thousand, three hundred six".