166173985 has 8 divisors (see below), whose sum is σ = 199538280. Its totient is φ = 132852864.

The previous prime is 166173983. The next prime is 166173991. The reversal of 166173985 is 589371661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 73441 + 166100544 = 271^2 + 12888^2 .

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 166173985 - 2¹ = 166173983 is a prime.

It is a super-2 number, since 2×166173985² = 55227586581560450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166173983) 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, 1612 + ... + 18301.

It is an arithmetic number, because the mean of its divisors is an integer number (24942285).

Almost surely, 2^166173985 is an apocalyptic number.

It is an amenable number.

166173985 is a deficient number, since it is larger than the sum of its proper divisors (33364295).

166173985 is a wasteful number, since it uses less digits than its factorization.

166173985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21587.

The product of its digits is 272160, while the sum is 46.

The square root of 166173985 is about 12890.8488859345. The cubic root of 166173985 is about 549.7784066004.

It can be divided in two parts, 16617 and 3985, that added together give a palindrome (20602).

The spelling of 166173985 in words is "one hundred sixty-six million, one hundred seventy-three thousand, nine hundred eighty-five".