18040999 has 4 divisors (see below), whose sum is σ = 18060336. Its totient is φ = 18021664.

The previous prime is 18040973. The next prime is 18041033. The reversal of 18040999 is 99904081.

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 18040999 - 2¹⁵ = 18008231 is a prime.

It is a super-3 number, since 3×18040999³ (a number of 23 digits) contains 333 as substring.

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 a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18040909) 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, 8194 + ... + 10159.

It is an arithmetic number, because the mean of its divisors is an integer number (4515084).

Almost surely, 2^18040999 is an apocalyptic number.

18040999 is a deficient number, since it is larger than the sum of its proper divisors (19337).

18040999 is an equidigital number, since it uses as much as digits as its factorization.

18040999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19336.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 18040999 is about 4247.4697173729. The cubic root of 18040999 is about 262.2729659038.

The spelling of 18040999 in words is "eighteen million, forty thousand, nine hundred ninety-nine".