It is a happy number.
It is a congruent number.
It is an unprimeable number.
21251000 is an apocalyptic number.
1251000 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 1251000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2129400).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1251000 is a wasteful number, since it uses less digits than its factorization.
1251000 is an evil number, because the sum of its binary digits is even.
The square root of 1251000 is about 1118.4811129384. The cubic root of 1251000 is about 107.7504526407.
Adding to 1251000 its reverse (1521), we get a palindrome (1252521).
The spelling of 1251000 in words is "one million, two hundred fifty-one thousand".