664539 has 8 divisors (see below), whose sum is σ = 924672. Its totient is φ = 423720.

The previous prime is 664537. The next prime is 664549. The reversal of 664539 is 935466.

It is a happy number.

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

It is not a de Polignac number, because 664539 - 2¹ = 664537 is a prime.

It is a super-2 number, since 2×664539² = 883224165042, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664539.

It is not an unprimeable number, because it can be changed into a prime (664537) 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, 4747 + ... + 4884.

It is an arithmetic number, because the mean of its divisors is an integer number (115584).

2⁶⁶⁴⁵³⁹ is an apocalyptic number.

664539 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

664539 is a deficient number, since it is larger than the sum of its proper divisors (260133).

664539 is a wasteful number, since it uses less digits than its factorization.

664539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9657.

The product of its digits is 19440, while the sum is 33.

The square root of 664539 is about 815.1926152757. The cubic root of 664539 is about 87.2650130295.

The spelling of 664539 in words is "six hundred sixty-four thousand, five hundred thirty-nine".