664718 has 8 divisors (see below), whose sum is σ = 1005312. Its totient is φ = 329616.

The previous prime is 664711. The next prime is 664739. The reversal of 664718 is 817466.

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664718.

It is not an unprimeable number, because it can be changed into a prime (664711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1055 + ... + 1562.

It is an arithmetic number, because the mean of its divisors is an integer number (125664).

2⁶⁶⁴⁷¹⁸ is an apocalyptic number.

664718 is a deficient number, since it is larger than the sum of its proper divisors (340594).

664718 is a wasteful number, since it uses less digits than its factorization.

664718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2746.

The product of its digits is 8064, while the sum is 32.

The square root of 664718 is about 815.3023978868. The cubic root of 664718 is about 87.2728475509.

The spelling of 664718 in words is "six hundred sixty-four thousand, seven hundred eighteen".