665065 has 4 divisors (see below), whose sum is σ = 798084. Its totient is φ = 532048.

The previous prime is 665053. The next prime is 665069. The reversal of 665065 is 560566.

665065 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 2 ways, for example, as 290521 + 374544 = 539^2 + 612^2 .

It is a cyclic number.

It is not a de Polignac number, because 665065 - 2¹⁵ = 632297 is a prime.

It is a super-2 number, since 2×665065² = 884622908450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66502 + ... + 66511.

It is an arithmetic number, because the mean of its divisors is an integer number (199521).

2⁶⁶⁵⁰⁶⁵ is an apocalyptic number.

It is an amenable number.

665065 is a deficient number, since it is larger than the sum of its proper divisors (133019).

665065 is a wasteful number, since it uses less digits than its factorization.

665065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133018.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 665065 is about 815.5151745982. The cubic root of 665065 is about 87.2880311375.

The spelling of 665065 in words is "six hundred sixty-five thousand, sixty-five".