81493441280 has 288 divisors, whose sum is σ = 214210676736. Its totient is φ = 29578493952.

The previous prime is 81493441279. The next prime is 81493441283. The reversal of 81493441280 is 8214439418.

It is not an unprimeable number, because it can be changed into a prime (81493441283) 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 31 ways as a sum of consecutive naturals, for example, 102249842 + ... + 102250638.

It is an arithmetic number, because the mean of its divisors is an integer number (743787072).

Almost surely, 2^81493441280 is an apocalyptic number.

81493441280 is a gapful number since it is divisible by the number (80) 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 81493441280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107105338368).

81493441280 is an abundant number, since it is smaller than the sum of its proper divisors (132717235456).

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

81493441280 is a wasteful number, since it uses less digits than its factorization.

81493441280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999 (or 985 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 44.

The spelling of 81493441280 in words is "eighty-one billion, four hundred ninety-three million, four hundred forty-one thousand, two hundred eighty".