2001101211991 has 8 divisors (see below), whose sum is σ = 2294279438624. Its totient is φ = 1709749641600.

The previous prime is 2001101211929. The next prime is 2001101211997. The reversal of 2001101211991 is 1991121011002.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2001101211991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001101211997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 456661710 + ... + 456666091.

It is an arithmetic number, because the mean of its divisors is an integer number (286784929828).

Almost surely, 2^{2001101211991} is an apocalyptic number.

2001101211991 is a deficient number, since it is larger than the sum of its proper divisors (293178226633).

2001101211991 is an equidigital number, since it uses as much as digits as its factorization.

2001101211991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913328121.

The product of its (nonzero) digits is 324, while the sum is 28.

Adding to 2001101211991 its reverse (1991121011002), we get a palindrome (3992222222993).

The spelling of 2001101211991 in words is "two trillion, one billion, one hundred one million, two hundred eleven thousand, nine hundred ninety-one".