16608409 has 4 divisors (see below), whose sum is σ = 16880740. Its totient is φ = 16336080.

The previous prime is 16608377. The next prime is 16608457. The reversal of 16608409 is 90480661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90480661 = 31 ⋅2918731.

It can be written as a sum of positive squares in 2 ways, for example, as 327184 + 16281225 = 572^2 + 4035^2 .

It is a cyclic number.

It is not a de Polignac number, because 16608409 - 2⁵ = 16608377 is a prime.

It is a super-2 number, since 2×16608409² = 551678499022562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16608499) 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, 136074 + ... + 136195.

It is an arithmetic number, because the mean of its divisors is an integer number (4220185).

Almost surely, 2^16608409 is an apocalyptic number.

It is an amenable number.

16608409 is a deficient number, since it is larger than the sum of its proper divisors (272331).

16608409 is an equidigital number, since it uses as much as digits as its factorization.

16608409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272330.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 16608409 is about 4075.3415807758. The cubic root of 16608409 is about 255.1385073503.

The spelling of 16608409 in words is "sixteen million, six hundred eight thousand, four hundred nine".