18218384 has 10 divisors (see below), whose sum is σ = 35298150. Its totient is φ = 9109184.

The previous prime is 18218381. The next prime is 18218399. The reversal of 18218384 is 48381281.

It can be written as a sum of positive squares in only one way, i.e., 13690000 + 4528384 = 3700^2 + 2128^2 .

It is not an unprimeable number, because it can be changed into a prime (18218381) 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 as a sum of consecutive naturals, namely, 569309 + ... + 569340.

It is an arithmetic number, because the mean of its divisors is an integer number (3529815).

Almost surely, 2^18218384 is an apocalyptic number.

It is an amenable number.

18218384 is a deficient number, since it is larger than the sum of its proper divisors (17079766).

18218384 is a wasteful number, since it uses less digits than its factorization.

18218384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138657 (or 1138651 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 18218384 is about 4268.2998957430. The cubic root of 18218384 is about 263.1297484676.

The spelling of 18218384 in words is "eighteen million, two hundred eighteen thousand, three hundred eighty-four".