18059309 has 4 divisors (see below), whose sum is σ = 18096000. Its totient is φ = 18022620.

The previous prime is 18059303. The next prime is 18059317. The reversal of 18059309 is 90395081.

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: 90395081 = 7 ⋅12913583.

It is a cyclic number.

It is not a de Polignac number, because 18059309 - 2⁸ = 18059053 is a prime.

It is a super-2 number, since 2×18059309² = 652277283114962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18059303) 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, 17597 + ... + 18594.

It is an arithmetic number, because the mean of its divisors is an integer number (4524000).

Almost surely, 2^18059309 is an apocalyptic number.

It is an amenable number.

18059309 is a deficient number, since it is larger than the sum of its proper divisors (36691).

18059309 is an equidigital number, since it uses as much as digits as its factorization.

18059309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36690.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 18059309 is about 4249.6245716534. The cubic root of 18059309 is about 262.3616637694.

The spelling of 18059309 in words is "eighteen million, fifty-nine thousand, three hundred nine".