12638781773 has 6 divisors (see below), whose sum is σ = 13212186414. Its totient is φ = 12089269016.

The previous prime is 12638781761. The next prime is 12638781791. The reversal of 12638781773 is 37718783621.

It can be written as a sum of positive squares in only one way, i.e., 10717011529 + 1921770244 = 103523^2 + 43838^2 .

It is not a de Polignac number, because 12638781773 - 2⁸ = 12638781517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12638781373) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11945390 + ... + 11946447.

It is an arithmetic number, because the mean of its divisors is an integer number (2202031069).

Almost surely, 2^12638781773 is an apocalyptic number.

It is an amenable number.

12638781773 is a deficient number, since it is larger than the sum of its proper divisors (573404641).

12638781773 is an equidigital number, since it uses as much as digits as its factorization.

12638781773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23891883 (or 23891860 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 53.

The spelling of 12638781773 in words is "twelve billion, six hundred thirty-eight million, seven hundred eighty-one thousand, seven hundred seventy-three".