81532800 has 288 divisors, whose sum is σ = 308295000. Its totient is φ = 20459520.

The previous prime is 81532757. The next prime is 81532807. The reversal of 81532800 is 823518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81532807) by changing a digit.

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, 547126 + ... + 547274.

Almost surely, 2^81532800 is an apocalyptic number.

81532800 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 81532800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154147500).

81532800 is an abundant number, since it is smaller than the sum of its proper divisors (226762200).

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

81532800 is a wasteful number, since it uses less digits than its factorization.

81532800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81532800 is about 9029.5514838778. The cubic root of 81532800 is about 433.6214783095.

The spelling of 81532800 in words is "eighty-one million, five hundred thirty-two thousand, eight hundred".