664441 has 2 divisors, whose sum is σ = 664442. Its totient is φ = 664440.

The previous prime is 664427. The next prime is 664459. The reversal of 664441 is 144466.

664441 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 606841 + 57600 = 779^2 + 240^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664441 is a prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (664421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332220 + 332221.

It is an arithmetic number, because the mean of its divisors is an integer number (332221).

2⁶⁶⁴⁴⁴¹ is an apocalyptic number.

It is an amenable number.

664441 is a deficient number, since it is larger than the sum of its proper divisors (1).

664441 is an equidigital number, since it uses as much as digits as its factorization.

664441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 25.

The square root of 664441 is about 815.1325045660. The cubic root of 664441 is about 87.2607231424.

Adding to 664441 its sum of digits (25), we get a palindrome (664466).

The spelling of 664441 in words is "six hundred sixty-four thousand, four hundred forty-one".