665767 has 4 divisors (see below), whose sum is σ = 675216. Its totient is φ = 656320.

The previous prime is 665761. The next prime is 665773. The reversal of 665767 is 767566.

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

It is an interprime number because it is at equal distance from previous prime (665761) and next prime (665773).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665767 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665761) 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, 4618 + ... + 4759.

It is an arithmetic number, because the mean of its divisors is an integer number (168804).

2⁶⁶⁵⁷⁶⁷ is an apocalyptic number.

665767 is a deficient number, since it is larger than the sum of its proper divisors (9449).

665767 is an equidigital number, since it uses as much as digits as its factorization.

665767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9448.

The product of its digits is 52920, while the sum is 37.

The square root of 665767 is about 815.9454638639. The cubic root of 665767 is about 87.3187322222.

It can be divided in two parts, 6657 and 67, that added together give a square (6724 = 82²).

The spelling of 665767 in words is "six hundred sixty-five thousand, seven hundred sixty-seven".