664505 has 8 divisors (see below), whose sum is σ = 801792. Its totient is φ = 528688.

The previous prime is 664471. The next prime is 664507. The reversal of 664505 is 505466.

664505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 664505 - 2⁶ = 664441 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 9.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664505.

It is not an unprimeable number, because it can be changed into a prime (664507) 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, 1544 + ... + 1926.

It is an arithmetic number, because the mean of its divisors is an integer number (100224).

2⁶⁶⁴⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

664505 is a deficient number, since it is larger than the sum of its proper divisors (137287).

664505 is a wasteful number, since it uses less digits than its factorization.

664505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 664505 is about 815.1717610418. The cubic root of 664505 is about 87.2635247491.

The spelling of 664505 in words is "six hundred sixty-four thousand, five hundred five".