18040987 has 4 divisors (see below), whose sum is σ = 18663120. Its totient is φ = 17418856.

The previous prime is 18040973. The next prime is 18041033. The reversal of 18040987 is 78904081.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18040987 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14 and base 16.

It is not an unprimeable number, because it can be changed into a prime (18040907) 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, 311023 + ... + 311080.

It is an arithmetic number, because the mean of its divisors is an integer number (4665780).

Almost surely, 2^18040987 is an apocalyptic number.

18040987 is a deficient number, since it is larger than the sum of its proper divisors (622133).

18040987 is an equidigital number, since it uses as much as digits as its factorization.

18040987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622132.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 18040987 is about 4247.4683047670. The cubic root of 18040987 is about 262.2729077533.

The spelling of 18040987 in words is "eighteen million, forty thousand, nine hundred eighty-seven".