81804800 has 240 divisors, whose sum is σ = 255733632. Its totient is φ = 25190400.

The previous prime is 81804797. The next prime is 81804809. The reversal of 81804800 is 840818.

81804800 = T₁₄₁₉ + T₁₄₂₀ + ... + T₁₄₉₅.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81804809) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 985559 + ... + 985641.

Almost surely, 2^81804800 is an apocalyptic number.

81804800 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 81804800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127866816).

81804800 is an abundant number, since it is smaller than the sum of its proper divisors (173928832).

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

81804800 is a wasteful number, since it uses less digits than its factorization.

81804800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 81804800 is about 9044.6005992526. The cubic root of 81804800 is about 434.1031418306.

The spelling of 81804800 in words is "eighty-one million, eight hundred four thousand, eight hundred".