638147039 has 2 divisors, whose sum is σ = 638147040. Its totient is φ = 638147038.

The previous prime is 638147021. The next prime is 638147051. The reversal of 638147039 is 930741836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638147039 - 2²⁸ = 369711583 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 638146987 and 638147005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638147339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319073519 + 319073520.

It is an arithmetic number, because the mean of its divisors is an integer number (319073520).

Almost surely, 2^638147039 is an apocalyptic number.

638147039 is a deficient number, since it is larger than the sum of its proper divisors (1).

638147039 is an equidigital number, since it uses as much as digits as its factorization.

638147039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 638147039 is about 25261.5723778232. The cubic root of 638147039 is about 860.9413880207.

The spelling of 638147039 in words is "six hundred thirty-eight million, one hundred forty-seven thousand, thirty-nine".