665144 has 32 divisors (see below), whose sum is σ = 1339200. Its totient is φ = 309120.

The previous prime is 665141. The next prime is 665153. The reversal of 665144 is 441566.

It is a happy number.

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10874 + ... + 10934.

It is an arithmetic number, because the mean of its divisors is an integer number (41850).

2⁶⁶⁵¹⁴⁴ is an apocalyptic number.

It is an amenable number.

665144 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

665144 is a wasteful number, since it uses less digits than its factorization.

665144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 139 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

The square root of 665144 is about 815.5636088007. The cubic root of 665144 is about 87.2914871814.

The spelling of 665144 in words is "six hundred sixty-five thousand, one hundred forty-four".