664066 has 8 divisors (see below), whose sum is σ = 1072764. Its totient is φ = 306480.

The previous prime is 664061. The next prime is 664067. The reversal of 664066 is 660466.

664066 is nontrivially palindromic in base 5.

It can be written as a sum of positive squares in 2 ways, for example, as 632025 + 32041 = 795^2 + 179^2 .

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

It is not an unprimeable number, because it can be changed into a prime (664061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12745 + ... + 12796.

2⁶⁶⁴⁰⁶⁶ is an apocalyptic number.

664066 is a deficient number, since it is larger than the sum of its proper divisors (408698).

664066 is a wasteful number, since it uses less digits than its factorization.

664066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25556.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 664066 is about 814.9024481495. The cubic root of 664066 is about 87.2443038621.

Subtracting from 664066 its reverse (660466), we obtain a square (3600 = 60²).

The spelling of 664066 in words is "six hundred sixty-four thousand, sixty-six".