665271 has 12 divisors (see below), whose sum is σ = 968448. Its totient is φ = 440064.

The previous prime is 665267. The next prime is 665279. The reversal of 665271 is 172566.

665271 is a `hidden beast` number, since 6 + 652 + 7 + 1 = 666.

It is not a de Polignac number, because 665271 - 2² = 665267 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665279) 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 11 ways as a sum of consecutive naturals, for example, 1546 + ... + 1928.

It is an arithmetic number, because the mean of its divisors is an integer number (80704).

2⁶⁶⁵²⁷¹ is an apocalyptic number.

665271 is a deficient number, since it is larger than the sum of its proper divisors (303177).

665271 is a wasteful number, since it uses less digits than its factorization.

665271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582 (or 579 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 665271 is about 815.6414653510. The cubic root of 665271 is about 87.2970425265.

The spelling of 665271 in words is "six hundred sixty-five thousand, two hundred seventy-one".