16628809 has 2 divisors, whose sum is σ = 16628810. Its totient is φ = 16628808.

The previous prime is 16628791. The next prime is 16628813. The reversal of 16628809 is 90882661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12446784 + 4182025 = 3528^2 + 2045^2 .

It is an emirp because it is prime and its reverse (90882661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16628809 - 2⁷ = 16628681 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16628009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8314404 + 8314405.

It is an arithmetic number, because the mean of its divisors is an integer number (8314405).

Almost surely, 2^16628809 is an apocalyptic number.

It is an amenable number.

16628809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16628809 is an equidigital number, since it uses as much as digits as its factorization.

16628809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 16628809 is about 4077.8436703729. The cubic root of 16628809 is about 255.2429262622.

The spelling of 16628809 in words is "sixteen million, six hundred twenty-eight thousand, eight hundred nine".