2001001 has 4 divisors (see below), whose sum is σ = 2008404. Its totient is φ = 1993600.

The previous prime is 2000989. The next prime is 2001037. The reversal of 2001001 is 1001002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1001002 = 2 ⋅500501.

It can be written as a sum of positive squares in 2 ways, for example, as 561001 + 1440000 = 749^2 + 1200^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001001 - 2⁵ = 2000969 is a prime.

It is a pancake number, because a pancake can be divided into 2001001 parts by 2000 straight cuts.

It is a Duffinian number.

2001001 is a modest number, since divided by 1001 gives 2 as remainder.

It is not an unprimeable number, because it can be changed into a prime (2001101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3280 + ... + 3841.

It is an arithmetic number, because the mean of its divisors is an integer number (502101).

2^2001001 is an apocalyptic number.

It is an amenable number.

2001001 is a deficient number, since it is larger than the sum of its proper divisors (7403).

2001001 is an equidigital number, since it uses as much as digits as its factorization.

2001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7402.

The product of its (nonzero) digits is 2, while the sum is 4.

The square root of 2001001 is about 1414.5674250456. The cubic root of 2001001 is about 126.0131211665.

Adding to 2001001 its reverse (1001002), we get a palindrome (3002003).

Subtracting from 2001001 its reverse (1001002), we obtain a palindrome (999999).

Multiplying 2001001 by its reverse (1001002), we get a palindrome (2003006003002).

The spelling of 2001001 in words is "two million, one thousand, one".