19879897891 has 8 divisors (see below), whose sum is σ = 22738937184. Its totient is φ = 17025622080.

The previous prime is 19879897879. The next prime is 19879897927.

19879897891 is nontrivially palindromic in base 10.

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 19879897891 - 2⁹ = 19879897379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19879897841) 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 7 ways as a sum of consecutive naturals, for example, 1181920 + ... + 1198621.

It is an arithmetic number, because the mean of its divisors is an integer number (2842367148).

Almost surely, 2^19879897891 is an apocalyptic number.

19879897891 is a deficient number, since it is larger than the sum of its proper divisors (2859039293).

19879897891 is a wasteful number, since it uses less digits than its factorization.

19879897891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2381741.

The product of its digits is 164602368, while the sum is 76.

The spelling of 19879897891 in words is "nineteen billion, eight hundred seventy-nine million, eight hundred ninety-seven thousand, eight hundred ninety-one".