180665665 has 4 divisors (see below), whose sum is σ = 216798804. Its totient is φ = 144532528.

The previous prime is 180665663. The next prime is 180665671. The reversal of 180665665 is 566566081.

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 64112049 + 116553616 = 8007^2 + 10796^2 .

It is a cyclic number.

It is not a de Polignac number, because 180665665 - 2¹ = 180665663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (180665663) 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, 18066562 + ... + 18066571.

It is an arithmetic number, because the mean of its divisors is an integer number (54199701).

Almost surely, 2^180665665 is an apocalyptic number.

It is an amenable number.

180665665 is a deficient number, since it is larger than the sum of its proper divisors (36133139).

180665665 is an equidigital number, since it uses as much as digits as its factorization.

180665665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36133138.

The product of its (nonzero) digits is 259200, while the sum is 43.

The square root of 180665665 is about 13441.1928414111. The cubic root of 180665665 is about 565.3167774855.

The spelling of 180665665 in words is "one hundred eighty million, six hundred sixty-five thousand, six hundred sixty-five".