It is a happy number.
It is a Jordan-Polya number, since it can be written as 6! ⋅ 4! ⋅ (2!)3.
It is a congruent number.
138240 is a Friedman number, since it can be written as 10*(8+2^4)^3, using all its digits and the basic arithmetic operations.
2138240 is an apocalyptic number.
138240 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 138240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245640).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
138240 is an equidigital number, since it uses as much as digits as its factorization.
138240 is an evil number, because the sum of its binary digits is even.
The square root of 138240 is about 371.8064012359. The cubic root of 138240 is about 51.7064325608.
The spelling of 138240 in words is "one hundred thirty-eight thousand, two hundred forty".