2001591441891 has 6 divisors (see below), whose sum is σ = 2891187638300. Its totient is φ = 1334394294588.

The previous prime is 2001591441887. The next prime is 2001591441893. The reversal of 2001591441891 is 1981441951002.

It is a happy number.

2001591441891 is a `hidden beast` number, since 2 + 0 + 0 + 1 + 591 + 44 + 18 + 9 + 1 = 666.

It is not a de Polignac number, because 2001591441891 - 2² = 2001591441887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001591441893) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 111199524541 + ... + 111199524558.

Almost surely, 2^{2001591441891} is an apocalyptic number.

2001591441891 is a deficient number, since it is larger than the sum of its proper divisors (889596196409).

2001591441891 is a wasteful number, since it uses less digits than its factorization.

2001591441891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222399049105 (or 222399049102 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 2001591441891 in words is "two trillion, one billion, five hundred ninety-one million, four hundred forty-one thousand, eight hundred ninety-one".