665166566 has 16 divisors (see below), whose sum is σ = 1034062848. Its totient is φ = 320565000.

The previous prime is 665166529. The next prime is 665166571. The reversal of 665166566 is 665661566.

It is a self number, because there is not a number n which added to its sum of digits gives 665166566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5810 + ... + 36933.

It is an arithmetic number, because the mean of its divisors is an integer number (64628928).

Almost surely, 2^665166566 is an apocalyptic number.

665166566 is a deficient number, since it is larger than the sum of its proper divisors (368896282).

665166566 is a wasteful number, since it uses less digits than its factorization.

665166566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43027.

The product of its digits is 1166400, while the sum is 47.

The square root of 665166566 is about 25790.8232904652. The cubic root of 665166566 is about 872.9247433473.

The spelling of 665166566 in words is "six hundred sixty-five million, one hundred sixty-six thousand, five hundred sixty-six".