1021001 has 2 divisors, whose sum is σ = 1021002.
Its totient is φ = 1021000.
The previous prime is 1020997. The next prime is 1021019. The reversal of 1021001 is 1001201.
It is a happy number.
1021001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 990025 + 30976 = 995^2 + 176^2
It is a cyclic number.
It is not a de Polignac number, because 1021001 - 22 = 1020997 is a prime.
It is not a weakly prime, because it can be changed into another prime (1021081) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510500 + 510501.
It is an arithmetic number, because the mean of its divisors is an integer number (510501).
21021001 is an apocalyptic number.
It is an amenable number.
1021001 is a deficient number, since it is larger than the sum of its proper divisors (1).
1021001 is an equidigital number, since it uses as much as digits as its factorization.
1021001 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 2, while the sum is 5.
The square root of 1021001 is about 1010.4459411567.
The cubic root of 1021001 is about 100.6951892531.
Adding to 1021001 its reverse (1001201), we get a palindrome (2022202).
Multiplying 1021001 by its reverse (1001201), we get a palindrome (1022227222201).
The spelling of 1021001 in words is "one million, twenty-one thousand, one".