19728424 has 8 divisors (see below), whose sum is σ = 36990810. Its totient is φ = 9864208.

The previous prime is 19728413. The next prime is 19728427. The reversal of 19728424 is 42482791.

It can be written as a sum of positive squares in only one way, i.e., 13823524 + 5904900 = 3718^2 + 2430^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (19728427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1233019 + ... + 1233034.

Almost surely, 2^19728424 is an apocalyptic number.

It is an amenable number.

19728424 is a deficient number, since it is larger than the sum of its proper divisors (17262386).

19728424 is a wasteful number, since it uses less digits than its factorization.

19728424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2466059 (or 2466055 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 19728424 is about 4441.6690556591. The cubic root of 19728424 is about 270.2075404750.

The spelling of 19728424 in words is "nineteen million, seven hundred twenty-eight thousand, four hundred twenty-four".