16666550666 has 4 divisors (see below), whose sum is σ = 24999826002. Its totient is φ = 8333275332.

The previous prime is 16666550657. The next prime is 16666550669. The reversal of 16666550666 is 66605566661.

16666550666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 10501945441 + 6164605225 = 102479^2 + 78515^2 .

It is a super-2 number, since 2×16666550666² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16666550669) 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 as a sum of consecutive naturals, namely, 4166637665 + ... + 4166637668.

Almost surely, 2^16666550666 is an apocalyptic number.

16666550666 is a deficient number, since it is larger than the sum of its proper divisors (8333275336).

16666550666 is an equidigital number, since it uses as much as digits as its factorization.

16666550666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8333275335.

The product of its (nonzero) digits is 6998400, while the sum is 53.

The spelling of 16666550666 in words is "sixteen billion, six hundred sixty-six million, five hundred fifty thousand, six hundred sixty-six".