18086309 has 4 divisors (see below), whose sum is σ = 19038240. Its totient is φ = 17134380.

The previous prime is 18086279. The next prime is 18086357. The reversal of 18086309 is 90368081.

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: 90368081 = 23 ⋅3929047.

It is a cyclic number.

It is not a de Polignac number, because 18086309 - 2¹² = 18082213 is a prime.

It is a super-2 number, since 2×18086309² = 654229146486962, 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 (18086009) 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, 475937 + ... + 475974.

It is an arithmetic number, because the mean of its divisors is an integer number (4759560).

Almost surely, 2^18086309 is an apocalyptic number.

18086309 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18086309 is a deficient number, since it is larger than the sum of its proper divisors (951931).

18086309 is an equidigital number, since it uses as much as digits as its factorization.

18086309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951930.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 18086309 is about 4252.8001363807. The cubic root of 18086309 is about 262.4923486810.

The spelling of 18086309 in words is "eighteen million, eighty-six thousand, three hundred nine".