664546 has 4 divisors (see below), whose sum is σ = 996822. Its totient is φ = 332272.

The previous prime is 664537. The next prime is 664549. The reversal of 664546 is 645466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 622521 + 42025 = 789^2 + 205^2 .

It is a super-2 number, since 2×664546² = 883242772232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166135 + ... + 166138.

2⁶⁶⁴⁵⁴⁶ is an apocalyptic number.

664546 is a deficient number, since it is larger than the sum of its proper divisors (332276).

664546 is a wasteful number, since it uses less digits than its factorization.

664546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332275.

The product of its digits is 17280, while the sum is 31.

The square root of 664546 is about 815.1969087282. The cubic root of 664546 is about 87.2653194338.

The spelling of 664546 in words is "six hundred sixty-four thousand, five hundred forty-six".