It is a congruent number.
It is an unprimeable number.
Almost surely, 281537746120070 is an apocalyptic number.
It is a practical number, because each smaller number is the sum of distinct divisors of 81537746120070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100670432990400).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
81537746120070 is a wasteful number, since it uses less digits than its factorization.
81537746120070 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 40842.
The spelling of 81537746120070 in words is "eighty-one trillion, five hundred thirty-seven billion, seven hundred forty-six million, one hundred twenty thousand, seventy".