12720428 has 24 divisors (see below), whose sum is σ = 25620000. Its totient is φ = 5413248.

The previous prime is 12720427. The next prime is 12720439. The reversal of 12720428 is 82402721.

It is a junction number, because it is equal to n+sod(n) for n = 12720397 and 12720406.

It is not an unprimeable number, because it can be changed into a prime (12720427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2648 + ... + 5696.

It is an arithmetic number, because the mean of its divisors is an integer number (1067500).

Almost surely, 2^12720428 is an apocalyptic number.

It is an amenable number.

12720428 is an abundant number, since it is smaller than the sum of its proper divisors (12899572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12720428 is a wasteful number, since it uses less digits than its factorization.

12720428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3209 (or 3207 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 12720428 is about 3566.5709021412. The cubic root of 12720428 is about 233.4356820836.

The spelling of 12720428 in words is "twelve million, seven hundred twenty thousand, four hundred twenty-eight".