18189800640 has 560 divisors, whose sum is σ = 71271408384. Its totient is φ = 4367001600.

The previous prime is 18189800557. The next prime is 18189800669. The reversal of 18189800640 is 4600898181.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 37350477 + ... + 37350963.

Almost surely, 2^18189800640 is an apocalyptic number.

18189800640 is a gapful number since it is divisible by the number (10) 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 18189800640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35635704192).

18189800640 is an abundant number, since it is smaller than the sum of its proper divisors (53081607744).

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

18189800640 is a wasteful number, since it uses less digits than its factorization.

18189800640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658 (or 639 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The spelling of 18189800640 in words is "eighteen billion, one hundred eighty-nine million, eight hundred thousand, six hundred forty".