638318106869 has 2 divisors, whose sum is σ = 638318106870. Its totient is φ = 638318106868.

The previous prime is 638318106859. The next prime is 638318106911. The reversal of 638318106869 is 968601813836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 626768305969 + 11549800900 = 791687^2 + 107470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638318106869 is a prime.

It is a super-2 number, since 2×638318106869² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638318106859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319159053434 + 319159053435.

It is an arithmetic number, because the mean of its divisors is an integer number (319159053435).

Almost surely, 2^638318106869 is an apocalyptic number.

It is an amenable number.

638318106869 is a deficient number, since it is larger than the sum of its proper divisors (1).

638318106869 is an equidigital number, since it uses as much as digits as its factorization.

638318106869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8957952, while the sum is 59.

The spelling of 638318106869 in words is "six hundred thirty-eight billion, three hundred eighteen million, one hundred six thousand, eight hundred sixty-nine".