18381999900 has 72 divisors (see below), whose sum is σ = 58020286464. Its totient is φ = 4456241600.

The previous prime is 18381999851. The next prime is 18381999929. The reversal of 18381999900 is 999918381.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2781852 + ... + 2788451.

It is an arithmetic number, because the mean of its divisors is an integer number (805837312).

Almost surely, 2^18381999900 is an apocalyptic number.

18381999900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18381999900 is an abundant number, since it is smaller than the sum of its proper divisors (39638286564).

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

18381999900 is a wasteful number, since it uses less digits than its factorization.

18381999900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5570331 (or 5570324 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 57.

The spelling of 18381999900 in words is "eighteen billion, three hundred eighty-one million, nine hundred ninety-nine thousand, nine hundred".