664439 has 8 divisors (see below), whose sum is σ = 691968. Its totient is φ = 637560.

The previous prime is 664427. The next prime is 664441. The reversal of 664439 is 934466.

664439 = T₁₀₆ + T₁₀₇ + ... + T₁₇₂.

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 664439 - 2¹⁶ = 598903 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664459) 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, 3044 + ... + 3254.

It is an arithmetic number, because the mean of its divisors is an integer number (86496).

2⁶⁶⁴⁴³⁹ is an apocalyptic number.

664439 is a deficient number, since it is larger than the sum of its proper divisors (27529).

664439 is a wasteful number, since it uses less digits than its factorization.

664439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325.

The product of its digits is 15552, while the sum is 32.

The square root of 664439 is about 815.1312777706. The cubic root of 664439 is about 87.2606355893.

The spelling of 664439 in words is "six hundred sixty-four thousand, four hundred thirty-nine".