166550985 has 36 divisors (see below), whose sum is σ = 299835588. Its totient is φ = 88809696.

The previous prime is 166550977. The next prime is 166550999. The reversal of 166550985 is 589055661.

It is a happy number.

166550985 is a `hidden beast` number, since 1 + 6 + 6 + 550 + 98 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 121352256 + 45198729 = 11016^2 + 6723^2 .

It is not a de Polignac number, because 166550985 - 2³ = 166550977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 166550985.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 30267 + ... + 35343.

Almost surely, 2^166550985 is an apocalyptic number.

166550985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166550985 is a deficient number, since it is larger than the sum of its proper divisors (133284603).

166550985 is an frugal number, since it uses more digits than its factorization.

166550985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5106 (or 5085 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The square root of 166550985 is about 12905.4633779652. The cubic root of 166550985 is about 550.1938545305.

It can be divided in two parts, 1665 and 50985, that added together give a triangular number (52650 = T₃₂₄).

The spelling of 166550985 in words is "one hundred sixty-six million, five hundred fifty thousand, nine hundred eighty-five".