19994159808 has 336 divisors, whose sum is σ = 68850662400. Its totient is φ = 5423818752.

The previous prime is 19994159777. The next prime is 19994159827. The reversal of 19994159808 is 80895149991.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (63).

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, 13816941 + ... + 13818387.

Almost surely, 2^19994159808 is an apocalyptic number.

19994159808 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 19994159808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34425331200).

19994159808 is an abundant number, since it is smaller than the sum of its proper divisors (48856502592).

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

19994159808 is a wasteful number, since it uses less digits than its factorization.

19994159808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644 (or 1631 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 63.

The spelling of 19994159808 in words is "nineteen billion, nine hundred ninety-four million, one hundred fifty-nine thousand, eight hundred eight".