It is a happy number.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1010021 is a prime.
It is a Duffinian number.
It is a Curzon number.
It is a congruent number.
21010021 is an apocalyptic number.
It is an amenable number.
1010021 is a wasteful number, since it uses less digits than its factorization.
1010021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 148.
The square root of 1010021 is about 1004.9980099483. The cubic root of 1010021 is about 100.3329237213.
Adding to 1010021 its reverse (1200101), we get a palindrome (2210122).
Multiplying 1010021 by its reverse (1200101), we get a palindrome (1212127212121).
The spelling of 1010021 in words is "one million, ten thousand, twenty-one".