664345 has 16 divisors (see below), whose sum is σ = 891648. Its totient is φ = 471040.

The previous prime is 664331. The next prime is 664357. The reversal of 664345 is 543466.

It is not a de Polignac number, because 664345 - 2¹³ = 656153 is a prime.

It is a Duffinian number.

Its product of digits (8640) is a multiple of the sum of its prime divisors (320).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2457 + ... + 2713.

It is an arithmetic number, because the mean of its divisors is an integer number (55728).

2⁶⁶⁴³⁴⁵ is an apocalyptic number.

It is an amenable number.

664345 is a deficient number, since it is larger than the sum of its proper divisors (227303).

664345 is a wasteful number, since it uses less digits than its factorization.

664345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320.

The product of its digits is 8640, while the sum is 28.

The square root of 664345 is about 815.0736163071. The cubic root of 664345 is about 87.2565203951.

The spelling of 664345 in words is "six hundred sixty-four thousand, three hundred forty-five".