It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a congruent number.
21001000 is an apocalyptic number.
1001000 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 1001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1572480).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1001000 is a wasteful number, since it uses less digits than its factorization.
1001000 is an odious number, because the sum of its binary digits is odd.
The square root of 1001000 is about 1000.4998750625. The cubic root of 1001000 is about 100.0333222284.
Adding to 1001000 its reverse (1001), we get a palindrome (1002001).
Subtracting from 1001000 its reverse (1001), we obtain a palindrome (999999).
1001000 divided by its reverse (1001) gives a cube (1000 = 103).
The spelling of 1001000 in words is "one million, one thousand".