16665599 has 2 divisors, whose sum is σ = 16665600. Its totient is φ = 16665598.

The previous prime is 16665581. The next prime is 16665601. The reversal of 16665599 is 99556661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16665599 is a prime.

Together with 16665601, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16665529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8332799 + 8332800.

It is an arithmetic number, because the mean of its divisors is an integer number (8332800).

Almost surely, 2^16665599 is an apocalyptic number.

16665599 is a deficient number, since it is larger than the sum of its proper divisors (1).

16665599 is an equidigital number, since it uses as much as digits as its factorization.

16665599 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 437400, while the sum is 47.

The square root of 16665599 is about 4082.3521406170. The cubic root of 16665599 is about 255.4310229278.

The spelling of 16665599 in words is "sixteen million, six hundred sixty-five thousand, five hundred ninety-nine".