166681985 has 8 divisors (see below), whose sum is σ = 200154240. Its totient is φ = 133255024.

The previous prime is 166681973. The next prime is 166682023. The reversal of 166681985 is 589186661.

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 166681985 - 2¹⁴ = 166665601 is a prime.

It is a Curzon 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, 2615 + ... + 18444.

It is an arithmetic number, because the mean of its divisors is an integer number (25019280).

Almost surely, 2^166681985 is an apocalyptic number.

It is an amenable number.

166681985 is a deficient number, since it is larger than the sum of its proper divisors (33472255).

166681985 is a wasteful number, since it uses less digits than its factorization.

166681985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22647.

The product of its digits is 622080, while the sum is 50.

The square root of 166681985 is about 12910.5377502256. The cubic root of 166681985 is about 550.3380676400.

The spelling of 166681985 in words is "one hundred sixty-six million, six hundred eighty-one thousand, nine hundred eighty-five".