664123 has 2 divisors, whose sum is σ = 664124. Its totient is φ = 664122.

The previous prime is 664121. The next prime is 664133. The reversal of 664123 is 321466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664123 - 2¹ = 664121 is a prime.

Together with 664121, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 664094 and 664103.

It is not a weakly prime, because it can be changed into another prime (664121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332061 + 332062.

It is an arithmetic number, because the mean of its divisors is an integer number (332062).

2⁶⁶⁴¹²³ is an apocalyptic number.

664123 is a deficient number, since it is larger than the sum of its proper divisors (1).

664123 is an equidigital number, since it uses as much as digits as its factorization.

664123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 22.

The square root of 664123 is about 814.9374209103. The cubic root of 664123 is about 87.2467999910.

Adding to 664123 its reverse (321466), we get a palindrome (985589).

It can be divided in two parts, 664 and 123, that added together give a palindrome (787).

The spelling of 664123 in words is "six hundred sixty-four thousand, one hundred twenty-three".