638723443 has 2 divisors, whose sum is σ = 638723444. Its totient is φ = 638723442.

The previous prime is 638723441. The next prime is 638723483. The reversal of 638723443 is 344327836.

It is an a-pointer prime, because the next prime (638723483) can be obtained adding 638723443 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638723443 - 2¹ = 638723441 is a prime.

Together with 638723441, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 638723396 and 638723405.

It is not a weakly prime, because it can be changed into another prime (638723441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319361721 + 319361722.

It is an arithmetic number, because the mean of its divisors is an integer number (319361722).

Almost surely, 2^638723443 is an apocalyptic number.

638723443 is a deficient number, since it is larger than the sum of its proper divisors (1).

638723443 is an equidigital number, since it uses as much as digits as its factorization.

638723443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 40.

The square root of 638723443 is about 25272.9785146112. The cubic root of 638723443 is about 861.2005240779.

The spelling of 638723443 in words is "six hundred thirty-eight million, seven hundred twenty-three thousand, four hundred forty-three".