1002001 has 27 divisors (see below), whose sum is σ = 1387323.
Its totient is φ = 720720.
The previous prime is 1001989. The next prime is 1002017.
1002001 = 15 + 25 + ... + 135.
The square root of 1002001 is 1001.
It is a perfect power (a square), and thus also a powerful number.
1002001 is nontrivially palindromic in base 10.
It can be written as a sum of positive squares in only one way, i.e., 148225 + 853776 = 385^2 + 924^2
It is not a de Polignac number, because 1002001 - 211 = 999953 is a prime.
It is not an unprimeable number, because it can be changed into a prime (1002061) by changing a digit.
It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 77071 + ... + 77083.
21002001 is an apocalyptic number.
1002001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.
1002001 is the 1001-st square number.
1002001 is the 501-st centered octagonal number.
It is an amenable number.
1002001 is a deficient number, since it is larger than the sum of its proper divisors (385322).
1002001 is a wasteful number, since it uses less digits than its factorization.
1002001 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 62 (or 31 counting only the distinct ones).
The product of its (nonzero) digits is 2, while the sum is 4.
The cubic root of 1002001 is about 100.0666555605.
The spelling of 1002001 in words is "one million, two thousand, one".