1666722166 has 8 divisors (see below), whose sum is σ = 2500484760. Its totient is φ = 833227248.

The previous prime is 1666722157. The next prime is 1666722179. The reversal of 1666722166 is 6612276661.

It is a happy number.

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

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, 50551 + ... + 76738.

It is an arithmetic number, because the mean of its divisors is an integer number (312560595).

Almost surely, 2^1666722166 is an apocalyptic number.

1666722166 is a deficient number, since it is larger than the sum of its proper divisors (833762594).

1666722166 is a wasteful number, since it uses less digits than its factorization.

1666722166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133838.

The product of its digits is 217728, while the sum is 43.

The square root of 1666722166 is about 40825.5087659664. The cubic root of 1666722166 is about 1185.6442616978.

The spelling of 1666722166 in words is "one billion, six hundred sixty-six million, seven hundred twenty-two thousand, one hundred sixty-six".