It is a tau number, because it is divible by the number of its divisors (36).
It is a plaindrome in base 16.
It is a nialpdrome in base 13.
It is a congruent number.
21980 is an apocalyptic number.
1980 is a gapful number since it is divisible by the number (10) 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 1980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3276).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1980 is a wasteful number, since it uses less digits than its factorization.
1980 is an evil number, because the sum of its binary digits is even.
The square root of 1980 is about 44.4971909226. The cubic root of 1980 is about 12.5570723564.
Subtracting from 1980 its reverse (891), we obtain a square (1089 = 332).
The spelling of 1980 in words is "one thousand, nine hundred eighty".