81180800 has 96 divisors (see below), whose sum is σ = 209450880. Its totient is φ = 31032320.

The previous prime is 81180791. The next prime is 81180811. The reversal of 81180800 is 808118.

It is a self number, because there is not a number n which added to its sum of digits gives 81180800.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73049 + ... + 74151.

It is an arithmetic number, because the mean of its divisors is an integer number (2181780).

Almost surely, 2^81180800 is an apocalyptic number.

81180800 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 81180800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104725440).

81180800 is an abundant number, since it is smaller than the sum of its proper divisors (128270080).

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

81180800 is a wasteful number, since it uses less digits than its factorization.

81180800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150 (or 1133 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 26.

The square root of 81180800 is about 9010.0388456432. The cubic root of 81180800 is about 432.9965562150.

Adding to 81180800 its reverse (808118), we get a palindrome (81988918).

The spelling of 81180800 in words is "eighty-one million, one hundred eighty thousand, eight hundred".