1666065666 has 8 divisors (see below), whose sum is σ = 3332131344. Its totient is φ = 555355220.

The previous prime is 1666065607. The next prime is 1666065677. The reversal of 1666065666 is 6665606661.

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

1666065666 is an admirable number.

It is a Curzon 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, 138838800 + ... + 138838811.

It is an arithmetic number, because the mean of its divisors is an integer number (416516418).

Almost surely, 2^1666065666 is an apocalyptic number.

1666065666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666065666 is a wasteful number, since it uses less digits than its factorization.

1666065666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277677616.

The product of its (nonzero) digits is 1399680, while the sum is 48.

The square root of 1666065666 is about 40817.4676578545. The cubic root of 1666065666 is about 1185.4885713467.

The spelling of 1666065666 in words is "one billion, six hundred sixty-six million, sixty-five thousand, six hundred sixty-six".