2001201212091 has 16 divisors (see below), whose sum is σ = 2707018715520. Its totient is φ = 1314837528000.

The previous prime is 2001201212057. The next prime is 2001201212099. The reversal of 2001201212091 is 1902121021002.

It is not a de Polignac number, because 2001201212091 - 2²¹ = 2001199114939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2001201212099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9723285 + ... + 9926966.

It is an arithmetic number, because the mean of its divisors is an integer number (169188669720).

Almost surely, 2^{2001201212091} is an apocalyptic number.

2001201212091 is a deficient number, since it is larger than the sum of its proper divisors (705817503429).

2001201212091 is a wasteful number, since it uses less digits than its factorization.

2001201212091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19650746.

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 2001201212091 its reverse (1902121021002), we get a palindrome (3903322233093).

The spelling of 2001201212091 in words is "two trillion, one billion, two hundred one million, two hundred twelve thousand, ninety-one".