638104757 has 2 divisors, whose sum is σ = 638104758. Its totient is φ = 638104756.

The previous prime is 638104729. The next prime is 638104781. The reversal of 638104757 is 757401836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 548215396 + 89889361 = 23414^2 + 9481^2 .

It is a cyclic number.

It is not a de Polignac number, because 638104757 - 2⁶ = 638104693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638104657) 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, 319052378 + 319052379.

It is an arithmetic number, because the mean of its divisors is an integer number (319052379).

Almost surely, 2^638104757 is an apocalyptic number.

It is an amenable number.

638104757 is a deficient number, since it is larger than the sum of its proper divisors (1).

638104757 is an equidigital number, since it uses as much as digits as its factorization.

638104757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 141120, while the sum is 41.

The square root of 638104757 is about 25260.7354801874. The cubic root of 638104757 is about 860.9223730051.

The spelling of 638104757 in words is "six hundred thirty-eight million, one hundred four thousand, seven hundred fifty-seven".