81118800 has 480 divisors, whose sum is σ = 350572800. Its totient is φ = 17418240.

The previous prime is 81118789. The next prime is 81118823. The reversal of 81118800 is 881118.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2192382 + ... + 2192418.

It is an arithmetic number, because the mean of its divisors is an integer number (730360).

Almost surely, 2^81118800 is an apocalyptic number.

81118800 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 81118800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175286400).

81118800 is an abundant number, since it is smaller than the sum of its proper divisors (269454000).

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

81118800 is a wasteful number, since it uses less digits than its factorization.

81118800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

The square root of 81118800 is about 9006.5975817730. The cubic root of 81118800 is about 432.8862976987.

Adding to 81118800 its reverse (881118), we get a palindrome (81999918).

It can be divided in two parts, 81118 and 800, that added together give a palindrome (81918).

The spelling of 81118800 in words is "eighty-one million, one hundred eighteen thousand, eight hundred".