81017493120 has 384 divisors, whose sum is σ = 289649318400. Its totient is φ = 20845486080.

The previous prime is 81017493083. The next prime is 81017493127. The reversal of 81017493120 is 2139471018.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81017493127) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 110528274 + ... + 110529006.

It is an arithmetic number, because the mean of its divisors is an integer number (754295100).

Almost surely, 2^81017493120 is an apocalyptic number.

81017493120 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 81017493120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144824659200).

81017493120 is an abundant number, since it is smaller than the sum of its proper divisors (208631825280).

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

81017493120 is a wasteful number, since it uses less digits than its factorization.

81017493120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408 (or 1393 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The spelling of 81017493120 in words is "eighty-one billion, seventeen million, four hundred ninety-three thousand, one hundred twenty".