19728871 has 8 divisors (see below), whose sum is σ = 20640384. Its totient is φ = 18821880.

The previous prime is 19728853. The next prime is 19728883. The reversal of 19728871 is 17882791.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19728871 - 2⁷ = 19728743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19728811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10420 + ... + 12166.

It is an arithmetic number, because the mean of its divisors is an integer number (2580048).

Almost surely, 2^19728871 is an apocalyptic number.

19728871 is a deficient number, since it is larger than the sum of its proper divisors (911513).

19728871 is a wasteful number, since it uses less digits than its factorization.

19728871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261.

The product of its digits is 56448, while the sum is 43.

The square root of 19728871 is about 4441.7193742964. The cubic root of 19728871 is about 270.2095812168.

The spelling of 19728871 in words is "nineteen million, seven hundred twenty-eight thousand, eight hundred seventy-one".