19969881871 has 4 divisors (see below), whose sum is σ = 20043571744. Its totient is φ = 19896192000.

The previous prime is 19969881821. The next prime is 19969881881. The reversal of 19969881871 is 17818896991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19969881871 - 2⁹ = 19969881359 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19969881797 and 19969881806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19969881821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36844530 + ... + 36845071.

It is an arithmetic number, because the mean of its divisors is an integer number (5010892936).

Almost surely, 2^19969881871 is an apocalyptic number.

19969881871 is a deficient number, since it is larger than the sum of its proper divisors (73689873).

19969881871 is an equidigital number, since it uses as much as digits as its factorization.

19969881871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73689872.

The product of its digits is 15676416, while the sum is 67.

The spelling of 19969881871 in words is "nineteen billion, nine hundred sixty-nine million, eight hundred eighty-one thousand, eight hundred seventy-one".