18189443972 has 12 divisors (see below), whose sum is σ = 36378888000. Its totient is φ = 7795475976.

The previous prime is 18189443971. The next prime is 18189444011. The reversal of 18189443972 is 27934498181.

It is a happy number.

18189443972 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (18189443971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 324811472 + ... + 324811527.

It is an arithmetic number, because the mean of its divisors is an integer number (3031574000).

Almost surely, 2^18189443972 is an apocalyptic number.

It is an amenable number.

18189443972 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18189443972 is a wasteful number, since it uses less digits than its factorization.

18189443972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649623010 (or 649623008 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 56.

The spelling of 18189443972 in words is "eighteen billion, one hundred eighty-nine million, four hundred forty-three thousand, nine hundred seventy-two".