12987793642 has 4 divisors (see below), whose sum is σ = 19481690466. Its totient is φ = 6493896820.

The previous prime is 12987793633. The next prime is 12987793649. The reversal of 12987793642 is 24639778921.

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., 12060652041 + 927141601 = 109821^2 + 30449^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (12987793649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3246948409 + ... + 3246948412.

Almost surely, 2^12987793642 is an apocalyptic number.

12987793642 is a deficient number, since it is larger than the sum of its proper divisors (6493896824).

12987793642 is an equidigital number, since it uses as much as digits as its factorization.

12987793642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6493896823.

The product of its digits is 9144576, while the sum is 58.

The spelling of 12987793642 in words is "twelve billion, nine hundred eighty-seven million, seven hundred ninety-three thousand, six hundred forty-two".