665459 has 4 divisors (see below), whose sum is σ = 694416. Its totient is φ = 636504.

The previous prime is 665447. The next prime is 665479. The reversal of 665459 is 954566.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665419) 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 3 ways as a sum of consecutive naturals, for example, 14444 + ... + 14489.

It is an arithmetic number, because the mean of its divisors is an integer number (173604).

2⁶⁶⁵⁴⁵⁹ is an apocalyptic number.

665459 is a deficient number, since it is larger than the sum of its proper divisors (28957).

665459 is a wasteful number, since it uses less digits than its factorization.

665459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28956.

The product of its digits is 32400, while the sum is 35.

The square root of 665459 is about 815.7567039259. The cubic root of 665459 is about 87.3052648891.

The spelling of 665459 in words is "six hundred sixty-five thousand, four hundred fifty-nine".