16663609 has 2 divisors, whose sum is σ = 16663610. Its totient is φ = 16663608.

The previous prime is 16663607. The next prime is 16663613. The reversal of 16663609 is 90636661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9903609 + 6760000 = 3147^2 + 2600^2 .

It is a cyclic number.

It is not a de Polignac number, because 16663609 - 2¹ = 16663607 is a prime.

Together with 16663607, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16663607) 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 as a sum of consecutive naturals, namely, 8331804 + 8331805.

It is an arithmetic number, because the mean of its divisors is an integer number (8331805).

Almost surely, 2^16663609 is an apocalyptic number.

It is an amenable number.

16663609 is a deficient number, since it is larger than the sum of its proper divisors (1).

16663609 is an equidigital number, since it uses as much as digits as its factorization.

16663609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 16663609 is about 4082.1084013044. The cubic root of 16663609 is about 255.4208557171.

The spelling of 16663609 in words is "sixteen million, six hundred sixty-three thousand, six hundred nine".