638725559 has 2 divisors, whose sum is σ = 638725560. Its totient is φ = 638725558.

The previous prime is 638725553. The next prime is 638725567. The reversal of 638725559 is 955527836.

638725559 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638725559 - 2⁴ = 638725543 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638725553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319362779 + 319362780.

It is an arithmetic number, because the mean of its divisors is an integer number (319362780).

Almost surely, 2^638725559 is an apocalyptic number.

638725559 is a deficient number, since it is larger than the sum of its proper divisors (1).

638725559 is an equidigital number, since it uses as much as digits as its factorization.

638725559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2268000, while the sum is 50.

The square root of 638725559 is about 25273.0203774697. The cubic root of 638725559 is about 861.2014750885.

The spelling of 638725559 in words is "six hundred thirty-eight million, seven hundred twenty-five thousand, five hundred fifty-nine".