12138172642 has 4 divisors (see below), whose sum is σ = 18207258966. Its totient is φ = 6069086320.

The previous prime is 12138172639. The next prime is 12138172643. The reversal of 12138172642 is 24627183121.

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., 12119587921 + 18584721 = 110089^2 + 4311^2 .

It is not an unprimeable number, because it can be changed into a prime (12138172643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3034543159 + ... + 3034543162.

Almost surely, 2^12138172642 is an apocalyptic number.

12138172642 is a deficient number, since it is larger than the sum of its proper divisors (6069086324).

12138172642 is an equidigital number, since it uses as much as digits as its factorization.

12138172642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6069086323.

The product of its digits is 32256, while the sum is 37.

The spelling of 12138172642 in words is "twelve billion, one hundred thirty-eight million, one hundred seventy-two thousand, six hundred forty-two".