19991395008 has 168 divisors, whose sum is σ = 61816821248. Its totient is φ = 6140510208.

The previous prime is 19991395003. The next prime is 19991395019. The reversal of 19991395008 is 80059319991.

19991395008 is a `hidden beast` number, since 19 + 9 + 91 + 39 + 500 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (19991395003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5037441 + ... + 5041407.

Almost surely, 2^19991395008 is an apocalyptic number.

19991395008 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 19991395008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30908410624).

19991395008 is an abundant number, since it is smaller than the sum of its proper divisors (41825426240).

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

19991395008 is a wasteful number, since it uses less digits than its factorization.

19991395008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4671 (or 4658 counting only the distinct ones).

The product of its (nonzero) digits is 787320, while the sum is 54.

The spelling of 19991395008 in words is "nineteen billion, nine hundred ninety-one million, three hundred ninety-five thousand, eight".