16628609 has 4 divisors (see below), whose sum is σ = 17351616. Its totient is φ = 15905604.

The previous prime is 16628603. The next prime is 16628641. The reversal of 16628609 is 90682661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16628609 - 2¹⁶ = 16563073 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (16628603) 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, 361469 + ... + 361514.

It is an arithmetic number, because the mean of its divisors is an integer number (4337904).

Almost surely, 2^16628609 is an apocalyptic number.

It is an amenable number.

16628609 is a deficient number, since it is larger than the sum of its proper divisors (723007).

16628609 is an equidigital number, since it uses as much as digits as its factorization.

16628609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723006.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 16628609 is about 4077.8191475346. The cubic root of 16628609 is about 255.2419029620.

The spelling of 16628609 in words is "sixteen million, six hundred twenty-eight thousand, six hundred nine".