81005360 has 80 divisors (see below), whose sum is σ = 200210400. Its totient is φ = 30394368.

The previous prime is 81005329. The next prime is 81005363. The reversal of 81005360 is 6350018.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (81005363) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 208046 + ... + 208434.

It is an arithmetic number, because the mean of its divisors is an integer number (2502630).

Almost surely, 2^81005360 is an apocalyptic number.

81005360 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 81005360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100105200).

81005360 is an abundant number, since it is smaller than the sum of its proper divisors (119205040).

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

81005360 is a wasteful number, since it uses less digits than its factorization.

81005360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 81005360 is about 9000.2977728517. The cubic root of 81005360 is about 432.6844146567.

Adding to 81005360 its reverse (6350018), we get a palindrome (87355378).

The spelling of 81005360 in words is "eighty-one million, five thousand, three hundred sixty".