81188800 has 168 divisors, whose sum is σ = 249448320. Its totient is φ = 25267200.

The previous prime is 81188741. The next prime is 81188819. The reversal of 81188800 is 888118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 122871 + ... + 123529.

Almost surely, 2^81188800 is an apocalyptic number.

81188800 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 81188800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124724160).

81188800 is an abundant number, since it is smaller than the sum of its proper divisors (168259520).

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

81188800 is a wasteful number, since it uses less digits than its factorization.

81188800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 684 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 34.

The square root of 81188800 is about 9010.4827839578. The cubic root of 81188800 is about 433.0107790307.

It can be divided in two parts, 81 and 188800, that added together give a palindrome (188881).

The spelling of 81188800 in words is "eighty-one million, one hundred eighty-eight thousand, eight hundred".