19728656 has 20 divisors (see below), whose sum is σ = 38874000. Its totient is φ = 9696672.

The previous prime is 19728629. The next prime is 19728697. The reversal of 19728656 is 65682791.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9506 + ... + 11393.

It is an arithmetic number, because the mean of its divisors is an integer number (1943700).

Almost surely, 2^19728656 is an apocalyptic number.

19728656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19728656 is a deficient number, since it is larger than the sum of its proper divisors (19145344).

19728656 is a wasteful number, since it uses less digits than its factorization.

19728656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20966 (or 20960 counting only the distinct ones).

The product of its digits is 181440, while the sum is 44.

The square root of 19728656 is about 4441.6951718910. The cubic root of 19728656 is about 270.2085996558.

The spelling of 19728656 in words is "nineteen million, seven hundred twenty-eight thousand, six hundred fifty-six".