18218478 has 32 divisors (see below), whose sum is σ = 37303200. Its totient is φ = 5930496.

The previous prime is 18218477. The next prime is 18218479. The reversal of 18218478 is 87481281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18218477) and next prime (18218479).

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18218477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58050 + ... + 58362.

It is an arithmetic number, because the mean of its divisors is an integer number (1165725).

Almost surely, 2^18218478 is an apocalyptic number.

18218478 is an abundant number, since it is smaller than the sum of its proper divisors (19084722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18218478 is a wasteful number, since it uses less digits than its factorization.

18218478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516.

The product of its digits is 28672, while the sum is 39.

The square root of 18218478 is about 4268.3109071388. The cubic root of 18218478 is about 263.1302010170.

The spelling of 18218478 in words is "eighteen million, two hundred eighteen thousand, four hundred seventy-eight".