81104400 has 180 divisors, whose sum is σ = 303280068. Its totient is φ = 19952640.

The previous prime is 81104389. The next prime is 81104423. The reversal of 81104400 is 440118.

It can be written as a sum of positive squares in 6 ways, for example, as 10342656 + 70761744 = 3216^2 + 8412^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 35 ways as a sum of consecutive naturals, for example, 45934 + ... + 47666.

Almost surely, 2^81104400 is an apocalyptic number.

81104400 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 81104400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151640034).

81104400 is an abundant number, since it is smaller than the sum of its proper divisors (222175668).

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

81104400 is a wasteful number, since it uses less digits than its factorization.

81104400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1770 (or 1756 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 81104400 is about 9005.7981323145. The cubic root of 81104400 is about 432.8606812301.

Adding to 81104400 its reverse (440118), we get a palindrome (81544518).

The spelling of 81104400 in words is "eighty-one million, one hundred four thousand, four hundred".