665847 has 32 divisors (see below), whose sum is σ = 1218560. Its totient is φ = 349920.

The previous prime is 665843. The next prime is 665857. The reversal of 665847 is 748566.

It is a happy number.

It is not a de Polignac number, because 665847 - 2² = 665843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2322 + ... + 2592.

It is an arithmetic number, because the mean of its divisors is an integer number (38080).

2⁶⁶⁵⁸⁴⁷ is an apocalyptic number.

665847 is a deficient number, since it is larger than the sum of its proper divisors (552713).

665847 is a wasteful number, since it uses less digits than its factorization.

665847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 294 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 665847 is about 815.9944852755. The cubic root of 665847 is about 87.3222295513.

The spelling of 665847 in words is "six hundred sixty-five thousand, eight hundred forty-seven".