It is an unprimeable number.
Almost surely, 281369877612800 is an apocalyptic number.
81369877612800 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 81369877612800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156331319394768).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
81369877612800 is a wasteful number, since it uses less digits than its factorization.
81369877612800 is an odious number, because the sum of its binary digits is odd.
The spelling of 81369877612800 in words is "eighty-one trillion, three hundred sixty-nine billion, eight hundred seventy-seven million, six hundred twelve thousand, eight hundred".