16672409 has 4 divisors (see below), whose sum is σ = 17954916. Its totient is φ = 15389904.

The previous prime is 16672391. The next prime is 16672417. The reversal of 16672409 is 90427661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90427661 = 167 ⋅541483.

It can be written as a sum of positive squares in 2 ways, for example, as 6451600 + 10220809 = 2540^2 + 3197^2 .

It is a cyclic number.

It is not a de Polignac number, because 16672409 - 2⁸ = 16672153 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16672499) 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, 641234 + ... + 641259.

It is an arithmetic number, because the mean of its divisors is an integer number (4488729).

Almost surely, 2^16672409 is an apocalyptic number.

It is an amenable number.

16672409 is a deficient number, since it is larger than the sum of its proper divisors (1282507).

16672409 is a wasteful number, since it uses less digits than its factorization.

16672409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282506.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 16672409 is about 4083.1861334012. The cubic root of 16672409 is about 255.4658101240.

The spelling of 16672409 in words is "sixteen million, six hundred seventy-two thousand, four hundred nine".