664365 has 16 divisors (see below), whose sum is σ = 1145088. Its totient is φ = 326976.

The previous prime is 664357. The next prime is 664369. The reversal of 664365 is 563466.

It is not a de Polignac number, because 664365 - 2³ = 664357 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664369) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1509 + ... + 1898.

It is an arithmetic number, because the mean of its divisors is an integer number (71568).

2⁶⁶⁴³⁶⁵ is an apocalyptic number.

664365 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

664365 is a deficient number, since it is larger than the sum of its proper divisors (480723).

664365 is a wasteful number, since it uses less digits than its factorization.

664365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3428.

The product of its digits is 12960, while the sum is 30.

The square root of 664365 is about 815.0858850453. The cubic root of 664365 is about 87.2573960009.

The spelling of 664365 in words is "six hundred sixty-four thousand, three hundred sixty-five".