16218309 has 4 divisors (see below), whose sum is σ = 21624416. Its totient is φ = 10812204.

The previous prime is 16218299. The next prime is 16218331. The reversal of 16218309 is 90381261.

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 not a de Polignac number, because 16218309 - 2¹¹ = 16216261 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16218409) 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, 2703049 + ... + 2703054.

It is an arithmetic number, because the mean of its divisors is an integer number (5406104).

Almost surely, 2^16218309 is an apocalyptic number.

It is an amenable number.

16218309 is a deficient number, since it is larger than the sum of its proper divisors (5406107).

16218309 is an equidigital number, since it uses as much as digits as its factorization.

16218309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5406106.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 16218309 is about 4027.1961710351. The cubic root of 16218309 is about 253.1250872123.

The spelling of 16218309 in words is "sixteen million, two hundred eighteen thousand, three hundred nine".