665312 has 24 divisors (see below), whose sum is σ = 1388016. Its totient is φ = 312832.

The previous prime is 665311. The next prime is 665351. The reversal of 665312 is 213566.

It is an Ulam 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 665312.

It is not an unprimeable number, because it can be changed into a prime (665311) 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, 68 + ... + 1155.

It is an arithmetic number, because the mean of its divisors is an integer number (57834).

2⁶⁶⁵³¹² is an apocalyptic number.

It is an amenable number.

665312 is an abundant number, since it is smaller than the sum of its proper divisors (722704).

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

665312 is a wasteful number, since it uses less digits than its factorization.

665312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1250 (or 1242 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 665312 is about 815.6665985561. Note that the first 3 decimals coincide. The cubic root of 665312 is about 87.2988358333.

Adding to 665312 its reverse (213566), we get a palindrome (878878).

The spelling of 665312 in words is "six hundred sixty-five thousand, three hundred twelve".