19728387 has 16 divisors (see below), whose sum is σ = 33402880. Its totient is φ = 11273256.

The previous prime is 19728377. The next prime is 19728389. The reversal of 19728387 is 78382791.

It is not a de Polignac number, because 19728387 - 2⁷ = 19728259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19728389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52003 + ... + 52380.

It is an arithmetic number, because the mean of its divisors is an integer number (2087680).

Almost surely, 2^19728387 is an apocalyptic number.

19728387 is a deficient number, since it is larger than the sum of its proper divisors (13674493).

19728387 is a wasteful number, since it uses less digits than its factorization.

19728387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104399 (or 104393 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 19728387 is about 4441.6648905562. The cubic root of 19728387 is about 270.2073715532.

The spelling of 19728387 in words is "nineteen million, seven hundred twenty-eight thousand, three hundred eighty-seven".