18808309 has 8 divisors (see below), whose sum is σ = 21321440. Its totient is φ = 16447536.

The previous prime is 18808303. The next prime is 18808333. The reversal of 18808309 is 90380881.

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 18808309 - 2³ = 18808301 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 (18808301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37827 + ... + 38320.

It is an arithmetic number, because the mean of its divisors is an integer number (2665180).

Almost surely, 2^18808309 is an apocalyptic number.

18808309 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18808309 is a deficient number, since it is larger than the sum of its proper divisors (2513131).

18808309 is a wasteful number, since it uses less digits than its factorization.

18808309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76179.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 18808309 is about 4336.8547358656. The cubic root of 18808309 is about 265.9397464672.

The spelling of 18808309 in words is "eighteen million, eight hundred eight thousand, three hundred nine".