664542 has 12 divisors (see below), whose sum is σ = 1439880. Its totient is φ = 221508.

The previous prime is 664537. The next prime is 664549. The reversal of 664542 is 245466.

It is a happy 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 664542.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18442 + ... + 18477.

It is an arithmetic number, because the mean of its divisors is an integer number (119990).

2⁶⁶⁴⁵⁴² is an apocalyptic number.

664542 is an abundant number, since it is smaller than the sum of its proper divisors (775338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664542 is a wasteful number, since it uses less digits than its factorization.

664542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36927 (or 36924 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 664542 is about 815.1944553295. The cubic root of 664542 is about 87.2651443459.

The spelling of 664542 in words is "six hundred sixty-four thousand, five hundred forty-two".