638501502797 has 2 divisors, whose sum is σ = 638501502798. Its totient is φ = 638501502796.

The previous prime is 638501502721. The next prime is 638501502809. The reversal of 638501502797 is 797205105836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 586310272681 + 52191230116 = 765709^2 + 228454^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638501502797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638501502097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319250751398 + 319250751399.

It is an arithmetic number, because the mean of its divisors is an integer number (319250751399).

Almost surely, 2^638501502797 is an apocalyptic number.

It is an amenable number.

638501502797 is a deficient number, since it is larger than the sum of its proper divisors (1).

638501502797 is an equidigital number, since it uses as much as digits as its factorization.

638501502797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3175200, while the sum is 53.

The spelling of 638501502797 in words is "six hundred thirty-eight billion, five hundred one million, five hundred two thousand, seven hundred ninety-seven".