18008709 has 4 divisors (see below), whose sum is σ = 24011616. Its totient is φ = 12005804.

The previous prime is 18008693. The next prime is 18008777. The reversal of 18008709 is 90780081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18008709 - 2⁴ = 18008693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18008709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18008209) 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, 3001449 + ... + 3001454.

It is an arithmetic number, because the mean of its divisors is an integer number (6002904).

Almost surely, 2^18008709 is an apocalyptic number.

It is an amenable number.

18008709 is a deficient number, since it is larger than the sum of its proper divisors (6002907).

18008709 is an equidigital number, since it uses as much as digits as its factorization.

18008709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6002906.

The product of its (nonzero) digits is 4032, while the sum is 33.

The square root of 18008709 is about 4243.6669284947. Note that the first 3 decimals coincide. The cubic root of 18008709 is about 262.1163993409.

The spelling of 18008709 in words is "eighteen million, eight thousand, seven hundred nine".