12728949638 has 4 divisors (see below), whose sum is σ = 19093424460. Its totient is φ = 6364474818.

The previous prime is 12728949599. The next prime is 12728949643. The reversal of 12728949638 is 83694982721.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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, 3182237408 + ... + 3182237411.

It is an arithmetic number, because the mean of its divisors is an integer number (4773356115).

Almost surely, 2^12728949638 is an apocalyptic number.

12728949638 is a deficient number, since it is larger than the sum of its proper divisors (6364474822).

12728949638 is an equidigital number, since it uses as much as digits as its factorization.

12728949638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6364474821.

The product of its digits is 10450944, while the sum is 59.

The spelling of 12728949638 in words is "twelve billion, seven hundred twenty-eight million, nine hundred forty-nine thousand, six hundred thirty-eight".