664509 has 8 divisors (see below), whose sum is σ = 889920. Its totient is φ = 441056.

The previous prime is 664507. The next prime is 664511. The reversal of 664509 is 905466.

It is an interprime number because it is at equal distance from previous prime (664507) and next prime (664511).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664509 - 2¹ = 664507 is a prime.

It is a super-2 number, since 2×664509² = 883144422162, which contains 22 as substring.

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 664509.

It is not an unprimeable number, because it can be changed into a prime (664507) 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 7 ways as a sum of consecutive naturals, for example, 769 + ... + 1385.

It is an arithmetic number, because the mean of its divisors is an integer number (111240).

2⁶⁶⁴⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

664509 is a deficient number, since it is larger than the sum of its proper divisors (225411).

664509 is a wasteful number, since it uses less digits than its factorization.

664509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 664509 is about 815.1742145088. The cubic root of 664509 is about 87.2636998435.

The spelling of 664509 in words is "six hundred sixty-four thousand, five hundred nine".