638023 has 2 divisors, whose sum is σ = 638024. Its totient is φ = 638022.

The previous prime is 637939. The next prime is 638047. The reversal of 638023 is 320836.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638023 is a prime.

It is an Ulam number.

638023 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 637985 and 638003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638063) 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, 319011 + 319012.

It is an arithmetic number, because the mean of its divisors is an integer number (319012).

2⁶³⁸⁰²³ is an apocalyptic number.

638023 is a deficient number, since it is larger than the sum of its proper divisors (1).

638023 is an equidigital number, since it uses as much as digits as its factorization.

638023 is an odious number, because the sum of its binary digits is odd.

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

The square root of 638023 is about 798.7634192926. The cubic root of 638023 is about 86.0885602952.

Adding to 638023 its reverse (320836), we get a palindrome (958859).

The spelling of 638023 in words is "six hundred thirty-eight thousand, twenty-three".