81983219472 has 1440 divisors, whose sum is σ = 333428659200. Its totient is φ = 19203609600.

The previous prime is 81983219459. The next prime is 81983219477. The reversal of 81983219472 is 27491238918.

81983219472 is a `hidden beast` number, since 81 + 9 + 83 + 2 + 19 + 472 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81983219477) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1154693197 + ... + 1154693267.

It is an arithmetic number, because the mean of its divisors is an integer number (231547680).

Almost surely, 2^81983219472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81983219472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166714329600).

81983219472 is an abundant number, since it is smaller than the sum of its proper divisors (251445439728).

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

81983219472 is a wasteful number, since it uses less digits than its factorization.

81983219472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 142 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The spelling of 81983219472 in words is "eighty-one billion, nine hundred eighty-three million, two hundred nineteen thousand, four hundred seventy-two".