665928 has 32 divisors (see below), whose sum is σ = 1850400. Its totient is φ = 221904.

The previous prime is 665923. The next prime is 665947. The reversal of 665928 is 829566.

665928 is a `hidden beast` number, since 66 + 592 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 665892 and 665901.

It is not an unprimeable number, because it can be changed into a prime (665921) by changing a digit.

665928 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1326 + ... + 1757.

It is an arithmetic number, because the mean of its divisors is an integer number (57825).

2⁶⁶⁵⁹²⁸ is an apocalyptic number.

It is an amenable number.

665928 is an abundant number, since it is smaller than the sum of its proper divisors (1184472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665928 is a wasteful number, since it uses less digits than its factorization.

665928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3098 (or 3088 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 665928 is about 816.0441164545. The cubic root of 665928 is about 87.3257703115.

The spelling of 665928 in words is "six hundred sixty-five thousand, nine hundred twenty-eight".