• 1000 is equal to the sum of all the digits of the numbers from 1 to 100, when written in hexadecimal.
• 1000 can be written using four 4's:
It is a happy number.
The cubic root of 1000 is 10.
1000 is nontrivially palindromic in base 9.
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
1000 is an undulating number in base 7.
1000 is a Rhonda number in base 16.
It is a plaindrome in base 13 and base 15.
It is a nialpdrome in base 4 and base 10.
1000 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 1000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1170).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1000 is an equidigital number, since it uses as much as digits as its factorization.
1000 is an evil number, because the sum of its binary digits is even.
The square root of 1000 is about 31.6227766017.
The spelling of 1000 in words is "one thousand", and thus it is an iban number.