163666585 has 4 divisors (see below), whose sum is σ = 196399908. Its totient is φ = 130933264.

The previous prime is 163666583. The next prime is 163666603. The reversal of 163666585 is 585666361.

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 124077321 + 39589264 = 11139^2 + 6292^2 .

It is a cyclic number.

It is not a de Polignac number, because 163666585 - 2¹ = 163666583 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163666583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16366654 + ... + 16366663.

It is an arithmetic number, because the mean of its divisors is an integer number (49099977).

Almost surely, 2^163666585 is an apocalyptic number.

It is an amenable number.

163666585 is a deficient number, since it is larger than the sum of its proper divisors (32733323).

163666585 is an equidigital number, since it uses as much as digits as its factorization.

163666585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32733322.

The product of its digits is 777600, while the sum is 46.

The square root of 163666585 is about 12793.2241831369. The cubic root of 163666585 is about 546.9991778310. Note that the first 3 decimals are identical.

The spelling of 163666585 in words is "one hundred sixty-three million, six hundred sixty-six thousand, five hundred eighty-five".