638330123 has 2 divisors, whose sum is σ = 638330124. Its totient is φ = 638330122.

The previous prime is 638330113. The next prime is 638330149. The reversal of 638330123 is 321033836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638330123 - 2¹⁰ = 638329099 is a prime.

It is not a weakly prime, because it can be changed into another prime (638330113) 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, 319165061 + 319165062.

It is an arithmetic number, because the mean of its divisors is an integer number (319165062).

Almost surely, 2^638330123 is an apocalyptic number.

638330123 is a deficient number, since it is larger than the sum of its proper divisors (1).

638330123 is an equidigital number, since it uses as much as digits as its factorization.

638330123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 29.

The square root of 638330123 is about 25265.1958828741. The cubic root of 638330123 is about 861.0237146694.

Adding to 638330123 its reverse (321033836), we get a palindrome (959363959).

The spelling of 638330123 in words is "six hundred thirty-eight million, three hundred thirty thousand, one hundred twenty-three".