It is a plaindrome in base 13.
It is a congruent number.
It is an unprimeable number.
231040 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 31040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37338).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
31040 is an equidigital number, since it uses as much as digits as its factorization.
31040 is an evil number, because the sum of its binary digits is even.
The square root of 31040 is about 176.1817243644. The cubic root of 31040 is about 31.4273120314.
Adding to 31040 its reverse (4013), we get a palindrome (35053).
The spelling of 31040 in words is "thirty-one thousand, forty".