19728975677 has 8 divisors (see below), whose sum is σ = 20890824696. Its totient is φ = 18567273472.

The previous prime is 19728975661. The next prime is 19728975697. The reversal of 19728975677 is 77657982791.

It can be written as a sum of positive squares in 4 ways, for example, as 13639670521 + 6089305156 = 116789^2 + 78034^2 .

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 19728975677 - 2⁴ = 19728975661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19728975647) 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 in 7 ways as a sum of consecutive naturals, for example, 366803 + ... + 417135.

It is an arithmetic number, because the mean of its divisors is an integer number (2611353087).

Almost surely, 2^19728975677 is an apocalyptic number.

19728975677 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19728975677 is a deficient number, since it is larger than the sum of its proper divisors (1161849019).

19728975677 is a wasteful number, since it uses less digits than its factorization.

19728975677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73407.

The product of its digits is 93350880, while the sum is 68.

The spelling of 19728975677 in words is "nineteen billion, seven hundred twenty-eight million, nine hundred seventy-five thousand, six hundred seventy-seven".