16665566 has 8 divisors (see below), whose sum is σ = 25408344. Its totient is φ = 8196120.

The previous prime is 16665563. The next prime is 16665581. The reversal of 16665566 is 66556661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68180 + ... + 68423.

It is an arithmetic number, because the mean of its divisors is an integer number (3176043).

Almost surely, 2^16665566 is an apocalyptic number.

16665566 is a deficient number, since it is larger than the sum of its proper divisors (8742778).

16665566 is a wasteful number, since it uses less digits than its factorization.

16665566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136666.

The product of its digits is 194400, while the sum is 41.

The square root of 16665566 is about 4082.3480988274. The cubic root of 16665566 is about 255.4308543324.

The spelling of 16665566 in words is "sixteen million, six hundred sixty-five thousand, five hundred sixty-six".