665385 has 16 divisors (see below), whose sum is σ = 1216896. Its totient is φ = 304128.

The previous prime is 665381. The next prime is 665387. The reversal of 665385 is 583566.

It is not a de Polignac number, because 665385 - 2² = 665381 is a prime.

665385 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (665381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3064 + ... + 3273.

It is an arithmetic number, because the mean of its divisors is an integer number (76056).

2⁶⁶⁵³⁸⁵ is an apocalyptic number.

It is an amenable number.

665385 is a deficient number, since it is larger than the sum of its proper divisors (551511).

665385 is a wasteful number, since it uses less digits than its factorization.

665385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6352.

The product of its digits is 21600, while the sum is 33.

The square root of 665385 is about 815.7113460042. The cubic root of 665385 is about 87.3020286121.

The spelling of 665385 in words is "six hundred sixty-five thousand, three hundred eighty-five".