665567 has 18 divisors (see below), whose sum is σ = 839952. Its totient is φ = 525504.

The previous prime is 665563. The next prime is 665569. The reversal of 665567 is 765566.

It is not a de Polignac number, because 665567 - 2² = 665563 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665567.

It is not an unprimeable number, because it can be changed into a prime (665563) 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 17 ways as a sum of consecutive naturals, for example, 14138 + ... + 14184.

It is an arithmetic number, because the mean of its divisors is an integer number (46664).

2⁶⁶⁵⁵⁶⁷ is an apocalyptic number.

665567 is a deficient number, since it is larger than the sum of its proper divisors (174385).

665567 is a wasteful number, since it uses less digits than its factorization.

665567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 71 counting only the distinct ones).

The product of its digits is 37800, while the sum is 35.

The square root of 665567 is about 815.8228974477. The cubic root of 665567 is about 87.3099876737.

Subtracting 665567 from its reverse (765566), we obtain a palindrome (99999).

The spelling of 665567 in words is "six hundred sixty-five thousand, five hundred sixty-seven".