121680 is an esthetic number in base 5, because in such base its adjacent digits differ by 1.
It is a tau number, because it is divible by the number of its divisors (90).
It is a congruent number.
121680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2121680 is an apocalyptic number.
121680 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 121680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221247).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121680 is a wasteful number, since it uses less digits than its factorization.
121680 is an odious number, because the sum of its binary digits is odd.
The square root of 121680 is about 348.8266044900. The cubic root of 121680 is about 49.5533553853.
The spelling of 121680 in words is "one hundred twenty-one thousand, six hundred eighty".