19991813088 has 144 divisors (see below), whose sum is σ = 57048074496. Its totient is φ = 6127280640.

The previous prime is 19991813087. The next prime is 19991813117. The reversal of 19991813088 is 88031819991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19991813087) 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 23 ways as a sum of consecutive naturals, for example, 4394431 + ... + 4398977.

It is an arithmetic number, because the mean of its divisors is an integer number (396167184).

Almost surely, 2^19991813088 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19991813088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28524037248).

19991813088 is an abundant number, since it is smaller than the sum of its proper divisors (37056261408).

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

19991813088 is a wasteful number, since it uses less digits than its factorization.

19991813088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4857 (or 4836 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 57.

The spelling of 19991813088 in words is "nineteen billion, nine hundred ninety-one million, eight hundred thirteen thousand, eighty-eight".