18004487 has 4 divisors (see below), whose sum is σ = 18423240. Its totient is φ = 17585736.

The previous prime is 18004477. The next prime is 18004507. The reversal of 18004487 is 78440081.

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

It is a cyclic number.

It is not a de Polignac number, because 18004487 - 2¹⁸ = 17742343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18004417) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 209312 + ... + 209397.

It is an arithmetic number, because the mean of its divisors is an integer number (4605810).

Almost surely, 2^18004487 is an apocalyptic number.

18004487 is a deficient number, since it is larger than the sum of its proper divisors (418753).

18004487 is an equidigital number, since it uses as much as digits as its factorization.

18004487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418752.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 18004487 is about 4243.1694521902. The cubic root of 18004487 is about 262.0959140314.

The spelling of 18004487 in words is "eighteen million, four thousand, four hundred eighty-seven".