2001101021001 has 12 divisors (see below), whose sum is σ = 2920278009012. Its totient is φ = 1320314075136.

The previous prime is 2001101020993. The next prime is 2001101021041. The reversal of 2001101021001 is 1001201011002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 353923857225 + 1647177163776 = 594915^2 + 1283424^2 .

It is not a de Polignac number, because 2001101021001 - 2³ = 2001101020993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (2001101021041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1146105096 + ... + 1146106841.

It is an arithmetic number, because the mean of its divisors is an integer number (243356500751).

Almost surely, 2^{2001101021001} is an apocalyptic number.

It is an amenable number.

2001101021001 is a deficient number, since it is larger than the sum of its proper divisors (919176988011).

2001101021001 is a wasteful number, since it uses less digits than its factorization.

2001101021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2292212040 (or 2292212037 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 2001101021001 its reverse (1001201011002), we get a palindrome (3002302032003).

Subtracting from 2001101021001 its reverse (1001201011002), we obtain a palindrome (999900009999).

The spelling of 2001101021001 in words is "two trillion, one billion, one hundred one million, twenty-one thousand, one".