166217689 has 8 divisors (see below), whose sum is σ = 182934432. Its totient is φ = 149768640.

The previous prime is 166217683. The next prime is 166217693. The reversal of 166217689 is 986712661.

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

It is a cyclic number.

It is not a de Polignac number, because 166217689 - 2¹³ = 166209497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166217683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65619 + ... + 68104.

It is an arithmetic number, because the mean of its divisors is an integer number (22866804).

Almost surely, 2^166217689 is an apocalyptic number.

It is an amenable number.

166217689 is a deficient number, since it is larger than the sum of its proper divisors (16716743).

166217689 is a wasteful number, since it uses less digits than its factorization.

166217689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133847.

The product of its digits is 217728, while the sum is 46.

The square root of 166217689 is about 12892.5439305049. The cubic root of 166217689 is about 549.8265998828.

It can be divided in two parts, 16621 and 7689, that added together give a triangular number (24310 = T₂₂₀).

The spelling of 166217689 in words is "one hundred sixty-six million, two hundred seventeen thousand, six hundred eighty-nine".