12638695181 has 4 divisors (see below), whose sum is σ = 14444223072. Its totient is φ = 10833167292.

The previous prime is 12638695171. The next prime is 12638695187. The reversal of 12638695181 is 18159683621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18159683621 = 89 ⋅204041389.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12638695181 is a prime.

It is a super-2 number, since 2×12638695181² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12638695187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 902763935 + ... + 902763948.

It is an arithmetic number, because the mean of its divisors is an integer number (3611055768).

Almost surely, 2^12638695181 is an apocalyptic number.

It is an amenable number.

12638695181 is a deficient number, since it is larger than the sum of its proper divisors (1805527891).

12638695181 is an equidigital number, since it uses as much as digits as its factorization.

12638695181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805527890.

The product of its digits is 622080, while the sum is 50.

The spelling of 12638695181 in words is "twelve billion, six hundred thirty-eight million, six hundred ninety-five thousand, one hundred eighty-one".