19681728 has 56 divisors (see below), whose sum is σ = 56814720. Its totient is φ = 5963520.

The previous prime is 19681723. The next prime is 19681771. The reversal of 19681728 is 82718691.

It is a self number, because there is not a number n which added to its sum of digits gives 19681728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681723) 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, 2548 + ... + 6771.

Almost surely, 2^19681728 is an apocalyptic number.

It is an amenable number.

19681728 is an abundant number, since it is smaller than the sum of its proper divisors (37132992).

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

19681728 is a wasteful number, since it uses less digits than its factorization.

19681728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9345 (or 9335 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 19681728 is about 4436.4093589298. The cubic root of 19681728 is about 269.9941836881.

The spelling of 19681728 in words is "nineteen million, six hundred eighty-one thousand, seven hundred twenty-eight".