664671 has 16 divisors (see below), whose sum is σ = 1046528. Its totient is φ = 367200.

The previous prime is 664669. The next prime is 664679. The reversal of 664671 is 176466.

664671 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 664671 - 2¹ = 664669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664679) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141 + ... + 1161.

It is an arithmetic number, because the mean of its divisors is an integer number (65408).

2⁶⁶⁴⁶⁷¹ is an apocalyptic number.

664671 is a deficient number, since it is larger than the sum of its proper divisors (381857).

664671 is a wasteful number, since it uses less digits than its factorization.

664671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062.

The product of its digits is 6048, while the sum is 30.

The square root of 664671 is about 815.2735737162. The cubic root of 664671 is about 87.2707905781.

It can be divided in two parts, 664 and 671, that multiplied together give a palindrome (445544).

The spelling of 664671 in words is "six hundred sixty-four thousand, six hundred seventy-one".