18044987 has 4 divisors (see below), whose sum is σ = 18053496. Its totient is φ = 18036480.

The previous prime is 18044981. The next prime is 18045019. The reversal of 18044987 is 78944081.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18044987 - 2⁸ = 18044731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18044981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1787 + ... + 6267.

It is an arithmetic number, because the mean of its divisors is an integer number (4513374).

Almost surely, 2^18044987 is an apocalyptic number.

18044987 is a deficient number, since it is larger than the sum of its proper divisors (8509).

18044987 is an equidigital number, since it uses as much as digits as its factorization.

18044987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8508.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 18044987 is about 4247.9391473984. The cubic root of 18044987 is about 262.2922898065.

Adding to 18044987 its sum of digits (41), we get a triangular number (18045028 = T₆₀₀₇).

The spelling of 18044987 in words is "eighteen million, forty-four thousand, nine hundred eighty-seven".