18851519808 has 168 divisors, whose sum is σ = 61510078656. Its totient is φ = 5464166400.

The previous prime is 18851519767. The next prime is 18851519821. The reversal of 18851519808 is 80891515881.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81048 + ... + 210408.

Almost surely, 2^18851519808 is an apocalyptic number.

18851519808 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 18851519808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30755039328).

18851519808 is an abundant number, since it is smaller than the sum of its proper divisors (42658558848).

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

18851519808 is a wasteful number, since it uses less digits than its factorization.

18851519808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129413 (or 129400 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 54.

The spelling of 18851519808 in words is "eighteen billion, eight hundred fifty-one million, five hundred nineteen thousand, eight hundred eight".