12720423728 has 20 divisors (see below), whose sum is σ = 24683933520. Its totient is φ = 6350376384.

The previous prime is 12720423721. The next prime is 12720423739. The reversal of 12720423728 is 82732402721.

It is a junction number, because it is equal to n+sod(n) for n = 12720423691 and 12720423700.

It is not an unprimeable number, because it can be changed into a prime (12720423721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 604043 + ... + 624746.

It is an arithmetic number, because the mean of its divisors is an integer number (1234196676).

Almost surely, 2^12720423728 is an apocalyptic number.

It is an amenable number.

12720423728 is a deficient number, since it is larger than the sum of its proper divisors (11963509792).

12720423728 is a wasteful number, since it uses less digits than its factorization.

12720423728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229444 (or 1229438 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 38.

The spelling of 12720423728 in words is "twelve billion, seven hundred twenty million, four hundred twenty-three thousand, seven hundred twenty-eight".