19969889868 has 144 divisors (see below), whose sum is σ = 55398077280. Its totient is φ = 6037420032.

The previous prime is 19969889843. The next prime is 19969889873. The reversal of 19969889868 is 86898896991.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15564355 + ... + 15565637.

It is an arithmetic number, because the mean of its divisors is an integer number (384708870).

Almost surely, 2^19969889868 is an apocalyptic number.

19969889868 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19969889868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27699038640).

19969889868 is an abundant number, since it is smaller than the sum of its proper divisors (35428187412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19969889868 is a wasteful number, since it uses less digits than its factorization.

19969889868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2216 (or 2211 counting only the distinct ones).

The product of its digits is 967458816, while the sum is 81.

The spelling of 19969889868 in words is "nineteen billion, nine hundred sixty-nine million, eight hundred eighty-nine thousand, eight hundred sixty-eight".