19989579878 has 8 divisors (see below), whose sum is σ = 29996131440. Its totient is φ = 9990869400.

The previous prime is 19989579877. The next prime is 19989579899. The reversal of 19989579878 is 87897598991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19989579877) 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, 1953893 + ... + 1964096.

It is an arithmetic number, because the mean of its divisors is an integer number (3749516430).

Almost surely, 2^19989579878 is an apocalyptic number.

19989579878 is a deficient number, since it is larger than the sum of its proper divisors (10006551562).

19989579878 is a wasteful number, since it uses less digits than its factorization.

19989579878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3920542.

The product of its digits is 823011840, while the sum is 80.

The spelling of 19989579878 in words is "nineteen billion, nine hundred eighty-nine million, five hundred seventy-nine thousand, eight hundred seventy-eight".