2001212122111 has 4 divisors (see below), whose sum is σ = 2002048402032. Its totient is φ = 2000375842192.

The previous prime is 2001212121973. The next prime is 2001212122139. The reversal of 2001212122111 is 1112212121002.

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 2001212122111 - 2³⁷ = 1863773168639 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 (2001212122141) 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, 418136371 + ... + 418141156.

It is an arithmetic number, because the mean of its divisors is an integer number (500512100508).

Almost surely, 2^{2001212122111} is an apocalyptic number.

2001212122111 is a deficient number, since it is larger than the sum of its proper divisors (836279921).

2001212122111 is an equidigital number, since it uses as much as digits as its factorization.

2001212122111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836279920.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2001212122111 its reverse (1112212121002), we get a palindrome (3113424243113).

It can be divided in two parts, 200121 and 2122111, that added together give a palindrome (2322232).

The spelling of 2001212122111 in words is "two trillion, one billion, two hundred twelve million, one hundred twenty-two thousand, one hundred eleven".