It is an ABA number since it can be written as A⋅BA, here for A=2, B=5000000.
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a Duffinian number.
It is a nialpdrome in base 10.
It is an unprimeable number.
Almost surely, 250000000000000 is an apocalyptic number.
50000000000000 is a gapful number since it is divisible by the number (50) 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 50000000000000
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
50000000000000 is an frugal number, since it uses more digits than its factorization.
50000000000000 is an odious number, because the sum of its binary digits is odd.