16809309 has 16 divisors (see below), whose sum is σ = 27167040. Its totient is φ = 10187280.

The previous prime is 16809307. The next prime is 16809323. The reversal of 16809309 is 90390861.

It is not a de Polignac number, because 16809309 - 2¹ = 16809307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16809301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28002 + ... + 28595.

It is an arithmetic number, because the mean of its divisors is an integer number (1697940).

Almost surely, 2^16809309 is an apocalyptic number.

It is an amenable number.

16809309 is a deficient number, since it is larger than the sum of its proper divisors (10357731).

16809309 is a wasteful number, since it uses less digits than its factorization.

16809309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56617 (or 56611 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 16809309 is about 4099.9157308413. The cubic root of 16809309 is about 256.1631294670.

The spelling of 16809309 in words is "sixteen million, eight hundred nine thousand, three hundred nine".