664975 has 12 divisors (see below), whose sum is σ = 838984. Its totient is φ = 522720.

The previous prime is 664973. The next prime is 664997. The reversal of 664975 is 579466.

664975 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 664975 - 2¹ = 664973 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1477 + ... + 1873.

2⁶⁶⁴⁹⁷⁵ is an apocalyptic number.

664975 is a deficient number, since it is larger than the sum of its proper divisors (174009).

664975 is a wasteful number, since it uses less digits than its factorization.

664975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474 (or 469 counting only the distinct ones).

The product of its digits is 45360, while the sum is 37.

The square root of 664975 is about 815.4599928874. The cubic root of 664975 is about 87.2840935388.

It can be divided in two parts, 6649 and 75, that added together give a square (6724 = 82²).

The spelling of 664975 in words is "six hundred sixty-four thousand, nine hundred seventy-five".