664072 has 8 divisors (see below), whose sum is σ = 1245150. Its totient is φ = 332032.

The previous prime is 664067. The next prime is 664091. The reversal of 664072 is 270466.

It can be written as a sum of positive squares in only one way, i.e., 538756 + 125316 = 734^2 + 354^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

664072 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 41497 + ... + 41512.

2⁶⁶⁴⁰⁷² is an apocalyptic number.

It is an amenable number.

664072 is a deficient number, since it is larger than the sum of its proper divisors (581078).

664072 is a wasteful number, since it uses less digits than its factorization.

664072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83015 (or 83011 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 664072 is about 814.9061295634. The cubic root of 664072 is about 87.2445666192.

The spelling of 664072 in words is "six hundred sixty-four thousand, seventy-two".