2001220101091 has 4 divisors (see below), whose sum is σ = 2001230465832. Its totient is φ = 2001209736352.

The previous prime is 2001220101073. The next prime is 2001220101103. The reversal of 2001220101091 is 1901010221002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2001220101091 - 2⁷ = 2001220100963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001220101011) 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, 4887145 + ... + 5280778.

It is an arithmetic number, because the mean of its divisors is an integer number (500307616458).

Almost surely, 2^{2001220101091} is an apocalyptic number.

2001220101091 is a deficient number, since it is larger than the sum of its proper divisors (10364741).

2001220101091 is a wasteful number, since it uses less digits than its factorization.

2001220101091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10364740.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 2001220101091 its reverse (1901010221002), we get a palindrome (3902230322093).

The spelling of 2001220101091 in words is "two trillion, one billion, two hundred twenty million, one hundred one thousand, ninety-one".