665018 has 4 divisors (see below), whose sum is σ = 997530. Its totient is φ = 332508.

The previous prime is 665017. The next prime is 665029. The reversal of 665018 is 810566.

665018 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 588289 + 76729 = 767^2 + 277^2 .

It is not an unprimeable number, because it can be changed into a prime (665011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166253 + ... + 166256.

2⁶⁶⁵⁰¹⁸ is an apocalyptic number.

665018 is a deficient number, since it is larger than the sum of its proper divisors (332512).

665018 is a wasteful number, since it uses less digits than its factorization.

665018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332511.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 665018 is about 815.4863579484. The cubic root of 665018 is about 87.2859748803.

The spelling of 665018 in words is "six hundred sixty-five thousand, eighteen".