664403 has 2 divisors, whose sum is σ = 664404. Its totient is φ = 664402.

The previous prime is 664381. The next prime is 664421. The reversal of 664403 is 304466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664403 - 2¹⁴ = 648019 is a prime.

It is a Sophie Germain prime.

It is an Ulam number.

It is a plaindrome in base 9.

It is not a weakly prime, because it can be changed into another prime (664603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332201 + 332202.

It is an arithmetic number, because the mean of its divisors is an integer number (332202).

2⁶⁶⁴⁴⁰³ is an apocalyptic number.

664403 is a deficient number, since it is larger than the sum of its proper divisors (1).

664403 is an equidigital number, since it uses as much as digits as its factorization.

664403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 664403 is about 815.1091951389. The cubic root of 664403 is about 87.2590596034.

Adding to 664403 its reverse (304466), we get a palindrome (968869).

The spelling of 664403 in words is "six hundred sixty-four thousand, four hundred three".