16809845 has 8 divisors (see below), whose sum is σ = 21723576. Its totient is φ = 12413376.

The previous prime is 16809841. The next prime is 16809853. The reversal of 16809845 is 54890861.

It can be written as a sum of positive squares in 4 ways, for example, as 1615441 + 15194404 = 1271^2 + 3898^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16809845 - 2² = 16809841 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16809841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129242 + ... + 129371.

It is an arithmetic number, because the mean of its divisors is an integer number (2715447).

Almost surely, 2^16809845 is an apocalyptic number.

It is an amenable number.

16809845 is a deficient number, since it is larger than the sum of its proper divisors (4913731).

16809845 is a wasteful number, since it uses less digits than its factorization.

16809845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258631.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 16809845 is about 4099.9810975174. The cubic root of 16809845 is about 256.1658522039.

The spelling of 16809845 in words is "sixteen million, eight hundred nine thousand, eight hundred forty-five".