81330842880 has 720 divisors, whose sum is σ = 339526387200. Its totient is φ = 18581778432.

The previous prime is 81330842843. The next prime is 81330842891. The reversal of 81330842880 is 8824803318.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×81330842880² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 35561097 + ... + 35563383.

Almost surely, 2^81330842880 is an apocalyptic number.

81330842880 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 81330842880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169763193600).

81330842880 is an abundant number, since it is smaller than the sum of its proper divisors (258195544320).

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

81330842880 is an equidigital number, since it uses as much as digits as its factorization.

81330842880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2341 (or 2304 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The spelling of 81330842880 in words is "eighty-one billion, three hundred thirty million, eight hundred forty-two thousand, eight hundred eighty".