81841132800 has 972 divisors, whose sum is σ = 344820805056. Its totient is φ = 18463334400.

The previous prime is 81841132733. The next prime is 81841132819. The reversal of 81841132800 is 823114818.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 301996665 + ... + 301996935.

Almost surely, 2^81841132800 is an apocalyptic number.

81841132800 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 81841132800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172410402528).

81841132800 is an abundant number, since it is smaller than the sum of its proper divisors (262979672256).

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

81841132800 is a wasteful number, since it uses less digits than its factorization.

81841132800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424 (or 395 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The spelling of 81841132800 in words is "eighty-one billion, eight hundred forty-one million, one hundred thirty-two thousand, eight hundred".