18423509 has 8 divisors (see below), whose sum is σ = 19998720. Its totient is φ = 16870896.

The previous prime is 18423491. The next prime is 18423533. The reversal of 18423509 is 90532481.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18423509 - 2¹² = 18419413 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 (18423539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3929 + ... + 7230.

It is an arithmetic number, because the mean of its divisors is an integer number (2499840).

Almost surely, 2^18423509 is an apocalyptic number.

It is an amenable number.

18423509 is a deficient number, since it is larger than the sum of its proper divisors (1575211).

18423509 is a wasteful number, since it uses less digits than its factorization.

18423509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11299.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 18423509 is about 4292.2615251170. The cubic root of 18423509 is about 264.1136113778.

The spelling of 18423509 in words is "eighteen million, four hundred twenty-three thousand, five hundred nine".