18549418 has 4 divisors (see below), whose sum is σ = 27824130. Its totient is φ = 9274708.

The previous prime is 18549409. The next prime is 18549449. The reversal of 18549418 is 81494581.

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., 15737089 + 2812329 = 3967^2 + 1677^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4637353 + ... + 4637356.

Almost surely, 2^18549418 is an apocalyptic number.

18549418 is a deficient number, since it is larger than the sum of its proper divisors (9274712).

18549418 is an equidigital number, since it uses as much as digits as its factorization.

18549418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9274711.

The product of its digits is 46080, while the sum is 40.

The square root of 18549418 is about 4306.9035280582. The cubic root of 18549418 is about 264.7139098355.

The spelling of 18549418 in words is "eighteen million, five hundred forty-nine thousand, four hundred eighteen".