12638582818 has 4 divisors (see below), whose sum is σ = 18957874230. Its totient is φ = 6319291408.

The previous prime is 12638582779. The next prime is 12638582837. The reversal of 12638582818 is 81828583621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81828583621 = 19 ⋅4306767559.

It can be written as a sum of positive squares in only one way, i.e., 12592655089 + 45927729 = 112217^2 + 6777^2 .

It is a super-2 number, since 2×12638582818² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3159645703 + ... + 3159645706.

Almost surely, 2^12638582818 is an apocalyptic number.

12638582818 is a deficient number, since it is larger than the sum of its proper divisors (6319291412).

12638582818 is an equidigital number, since it uses as much as digits as its factorization.

12638582818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6319291411.

The product of its digits is 1474560, while the sum is 52.

The spelling of 12638582818 in words is "twelve billion, six hundred thirty-eight million, five hundred eighty-two thousand, eight hundred eighteen".