638489 has 2 divisors, whose sum is σ = 638490. Its totient is φ = 638488.

The previous prime is 638467. The next prime is 638501. The reversal of 638489 is 984836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 444889 + 193600 = 667^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 638489 - 2⁸ = 638233 is a prime.

It is not a weakly prime, because it can be changed into another prime (638459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319244 + 319245.

It is an arithmetic number, because the mean of its divisors is an integer number (319245).

2⁶³⁸⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

638489 is a deficient number, since it is larger than the sum of its proper divisors (1).

638489 is an equidigital number, since it uses as much as digits as its factorization.

638489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 38.

The square root of 638489 is about 799.0550669384. The cubic root of 638489 is about 86.1095143497.

The spelling of 638489 in words is "six hundred thirty-eight thousand, four hundred eighty-nine".