638055317 has 2 divisors, whose sum is σ = 638055318. Its totient is φ = 638055316.

The previous prime is 638055307. The next prime is 638055337. The reversal of 638055317 is 713550836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 385690321 + 252364996 = 19639^2 + 15886^2 .

It is a cyclic number.

It is not a de Polignac number, because 638055317 - 2¹⁸ = 637793173 is a prime.

It is a super-2 number, since 2×638055317² = 814229175103940978, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638055307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319027658 + 319027659.

It is an arithmetic number, because the mean of its divisors is an integer number (319027659).

Almost surely, 2^638055317 is an apocalyptic number.

It is an amenable number.

638055317 is a deficient number, since it is larger than the sum of its proper divisors (1).

638055317 is an equidigital number, since it uses as much as digits as its factorization.

638055317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 638055317 is about 25259.7568673968. The cubic root of 638055317 is about 860.9001378360.

The spelling of 638055317 in words is "six hundred thirty-eight million, fifty-five thousand, three hundred seventeen".