81808588800 has 684 divisors, whose sum is σ = 312705738280. Its totient is φ = 20384317440.

The previous prime is 81808588783. The next prime is 81808588843. The reversal of 81808588800 is 888580818.

It is a tau number, because it is divible by the number of its divisors (684).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1120665564 + ... + 1120665636.

Almost surely, 2^81808588800 is an apocalyptic number.

81808588800 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 81808588800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156352869140).

81808588800 is an abundant number, since it is smaller than the sum of its proper divisors (230897149480).

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

81808588800 is an equidigital number, since it uses as much as digits as its factorization.

81808588800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 1310720, while the sum is 54.

The spelling of 81808588800 in words is "eighty-one billion, eight hundred eight million, five hundred eighty-eight thousand, eight hundred".