18494309 has 4 divisors (see below), whose sum is σ = 18717216. Its totient is φ = 18271404.

The previous prime is 18494303. The next prime is 18494347. The reversal of 18494309 is 90349481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90349481 = 6637 ⋅13613.

It is a cyclic number.

It is not a de Polignac number, because 18494309 - 2⁸ = 18494053 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18494303) 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, 111329 + ... + 111494.

It is an arithmetic number, because the mean of its divisors is an integer number (4679304).

Almost surely, 2^18494309 is an apocalyptic number.

It is an amenable number.

18494309 is a deficient number, since it is larger than the sum of its proper divisors (222907).

18494309 is an equidigital number, since it uses as much as digits as its factorization.

18494309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222906.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 18494309 is about 4300.5010173234. The cubic root of 18494309 is about 264.4515010723.

The spelling of 18494309 in words is "eighteen million, four hundred ninety-four thousand, three hundred nine".