18228478 has 4 divisors (see below), whose sum is σ = 27342720. Its totient is φ = 9114238.

The previous prime is 18228461. The next prime is 18228487. The reversal of 18228478 is 87482281.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18228478.

It is a congruent number.

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, 4557118 + ... + 4557121.

It is an arithmetic number, because the mean of its divisors is an integer number (6835680).

Almost surely, 2^18228478 is an apocalyptic number.

18228478 is a deficient number, since it is larger than the sum of its proper divisors (9114242).

18228478 is an equidigital number, since it uses as much as digits as its factorization.

18228478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9114241.

The product of its digits is 57344, while the sum is 40.

The square root of 18228478 is about 4269.4821700061. The cubic root of 18228478 is about 263.1783356768.

The spelling of 18228478 in words is "eighteen million, two hundred twenty-eight thousand, four hundred seventy-eight".