18919645400 has 24 divisors (see below), whose sum is σ = 43988176020. Its totient is φ = 7567858080.

The previous prime is 18919645369. The next prime is 18919645403. The reversal of 18919645400 is 454691981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18919645403) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 47298914 + ... + 47299313.

Almost surely, 2^18919645400 is an apocalyptic number.

18919645400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18919645400 is an abundant number, since it is smaller than the sum of its proper divisors (25068530620).

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

18919645400 is a wasteful number, since it uses less digits than its factorization.

18919645400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94598243 (or 94598234 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 47.

The spelling of 18919645400 in words is "eighteen billion, nine hundred nineteen million, six hundred forty-five thousand, four hundred".