12638017642 has 4 divisors (see below), whose sum is σ = 18957026466. Its totient is φ = 6319008820.

The previous prime is 12638017573. The next prime is 12638017649. The reversal of 12638017642 is 24671083621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 8641375681 + 3996641961 = 92959^2 + 63219^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 12638017595 and 12638017604.

It is not an unprimeable number, because it can be changed into a prime (12638017649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3159504409 + ... + 3159504412.

Almost surely, 2^12638017642 is an apocalyptic number.

12638017642 is a deficient number, since it is larger than the sum of its proper divisors (6319008824).

12638017642 is an equidigital number, since it uses as much as digits as its factorization.

12638017642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6319008823.

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 12638017642 in words is "twelve billion, six hundred thirty-eight million, seventeen thousand, six hundred forty-two".