1665606566 has 8 divisors (see below), whose sum is σ = 2690595264. Its totient is φ = 768741480.

The previous prime is 1665606517. The next prime is 1665606581. The reversal of 1665606566 is 6656065661.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1665606566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32030870 + ... + 32030921.

It is an arithmetic number, because the mean of its divisors is an integer number (336324408).

Almost surely, 2^1665606566 is an apocalyptic number.

1665606566 is a deficient number, since it is larger than the sum of its proper divisors (1024988698).

1665606566 is a wasteful number, since it uses less digits than its factorization.

1665606566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64061806.

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

The square root of 1665606566 is about 40811.8434526058. The cubic root of 1665606566 is about 1185.3796705165.

The spelling of 1665606566 in words is "one billion, six hundred sixty-five million, six hundred six thousand, five hundred sixty-six".