16909609 has 4 divisors (see below), whose sum is σ = 16972740. Its totient is φ = 16846480.

The previous prime is 16909591. The next prime is 16909631. The reversal of 16909609 is 90690961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90690961 = 911 ⋅99551.

It can be written as a sum of positive squares in 2 ways, for example, as 9363600 + 7546009 = 3060^2 + 2747^2 .

It is a cyclic number.

It is not a de Polignac number, because 16909609 - 2¹⁵ = 16876841 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16909699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31162 + ... + 31699.

It is an arithmetic number, because the mean of its divisors is an integer number (4243185).

Almost surely, 2^16909609 is an apocalyptic number.

It is an amenable number.

16909609 is a deficient number, since it is larger than the sum of its proper divisors (63131).

16909609 is an equidigital number, since it uses as much as digits as its factorization.

16909609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63130.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 16909609 is about 4112.1294969881. The cubic root of 16909609 is about 256.6716220628.

The spelling of 16909609 in words is "sixteen million, nine hundred nine thousand, six hundred nine".