166386985 has 4 divisors (see below), whose sum is σ = 199664388. Its totient is φ = 133109584.

The previous prime is 166386947. The next prime is 166386989. The reversal of 166386985 is 589683661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 91183401 + 75203584 = 9549^2 + 8672^2 .

It is a cyclic number.

It is not a de Polignac number, because 166386985 - 2¹⁷ = 166255913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166386989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16638694 + ... + 16638703.

It is an arithmetic number, because the mean of its divisors is an integer number (49916097).

Almost surely, 2^166386985 is an apocalyptic number.

It is an amenable number.

166386985 is a deficient number, since it is larger than the sum of its proper divisors (33277403).

166386985 is an equidigital number, since it uses as much as digits as its factorization.

166386985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33277402.

The product of its digits is 1866240, while the sum is 52.

The square root of 166386985 is about 12899.1079148909. The cubic root of 166386985 is about 550.0132062945.

The spelling of 166386985 in words is "one hundred sixty-six million, three hundred eighty-six thousand, nine hundred eighty-five".