12638900081 has 2 divisors, whose sum is σ = 12638900082. Its totient is φ = 12638900080.

The previous prime is 12638900003. The next prime is 12638900093. The reversal of 12638900081 is 18000983621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9437151025 + 3201749056 = 97145^2 + 56584^2 .

It is a cyclic number.

It is not a de Polignac number, because 12638900081 - 2²² = 12634705777 is a prime.

It is a super-2 number, since 2×12638900081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12638900381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6319450040 + 6319450041.

It is an arithmetic number, because the mean of its divisors is an integer number (6319450041).

Almost surely, 2^12638900081 is an apocalyptic number.

It is an amenable number.

12638900081 is a deficient number, since it is larger than the sum of its proper divisors (1).

12638900081 is an equidigital number, since it uses as much as digits as its factorization.

12638900081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 12638900081 in words is "twelve billion, six hundred thirty-eight million, nine hundred thousand, eighty-one".