2001021001 has 4 divisors (see below), whose sum is σ = 2286881152. Its totient is φ = 1715160852.

The previous prime is 2001020981. The next prime is 2001021053. The reversal of 2001021001 is 1001201002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2001021001 - 2¹⁵ = 2000988233 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7), and also a Moran number because the ratio is a prime number: 285860143 = 2001021001 / (2 + 0 + 0 + 1 + 0 + 2 + 1 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001021101) 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, 142930065 + ... + 142930078.

It is an arithmetic number, because the mean of its divisors is an integer number (571720288).

Almost surely, 2^2001021001 is an apocalyptic number.

It is an amenable number.

2001021001 is a deficient number, since it is larger than the sum of its proper divisors (285860151).

2001021001 is an equidigital number, since it uses as much as digits as its factorization.

2001021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285860150.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 2001021001 is about 44732.7732317146. The cubic root of 2001021001 is about 1260.1354101973.

Adding to 2001021001 its reverse (1001201002), we get a palindrome (3002222003).

It can be divided in two parts, 200 and 1021001, that added together give a palindrome (1021201).

The spelling of 2001021001 in words is "two billion, one million, twenty-one thousand, one".