19728264656 has 10 divisors (see below), whose sum is σ = 38223512802. Its totient is φ = 9864132320.

The previous prime is 19728264641. The next prime is 19728264659. The reversal of 19728264656 is 65646282791.

It can be written as a sum of positive squares in only one way, i.e., 13228680256 + 6499584400 = 115016^2 + 80620^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19728264659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 616508255 + ... + 616508286.

Almost surely, 2^19728264656 is an apocalyptic number.

19728264656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19728264656 is a deficient number, since it is larger than the sum of its proper divisors (18495248146).

19728264656 is a wasteful number, since it uses less digits than its factorization.

19728264656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233016549 (or 1233016543 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 56.

It can be divided in two parts, 1972 and 8264656, that added together give a palindrome (8266628).

The spelling of 19728264656 in words is "nineteen billion, seven hundred twenty-eight million, two hundred sixty-four thousand, six hundred fifty-six".