12638858347781 has 2 divisors, whose sum is σ = 12638858347782. Its totient is φ = 12638858347780.

The previous prime is 12638858347769. The next prime is 12638858347799. The reversal of 12638858347781 is 18774385883621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11822800864900 + 816057482881 = 3438430^2 + 903359^2 .

It is a cyclic number.

It is not a de Polignac number, because 12638858347781 - 2²⁶ = 12638791238917 is a prime.

It is a super-2 number, since 2×12638858347781² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12638858347711) 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, 6319429173890 + 6319429173891.

It is an arithmetic number, because the mean of its divisors is an integer number (6319429173891).

Almost surely, 2^{12638858347781} is an apocalyptic number.

It is an amenable number.

12638858347781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12638858347781 is an equidigital number, since it uses as much as digits as its factorization.

12638858347781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 433520640, while the sum is 71.

The spelling of 12638858347781 in words is "twelve trillion, six hundred thirty-eight billion, eight hundred fifty-eight million, three hundred forty-seven thousand, seven hundred eighty-one".