2001211111111 has 4 divisors (see below), whose sum is σ = 2010185152192. Its totient is φ = 1992237070032.

The previous prime is 2001211111093. The next prime is 2001211111129. The reversal of 2001211111111 is 1111111121002.

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

It is an interprime number because it is at equal distance from previous prime (2001211111093) and next prime (2001211111129).

It is a cyclic number.

It is not a de Polignac number, because 2001211111111 - 2⁵ = 2001211111079 is a prime.

It is a super-2 number, since 2×2001211111111² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

2001211111111 is a modest number, since divided by 1111111 gives 200121 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 2001211111091 and 2001211111100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001211112111) 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, 4487020206 + ... + 4487020651.

It is an arithmetic number, because the mean of its divisors is an integer number (502546288048).

Almost surely, 2^{2001211111111} is an apocalyptic number.

2001211111111 is a deficient number, since it is larger than the sum of its proper divisors (8974041081).

2001211111111 is an equidigital number, since it uses as much as digits as its factorization.

2001211111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8974041080.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 2001211111111 its reverse (1111111121002), we get a palindrome (3112322232113).

The spelling of 2001211111111 in words is "two trillion, one billion, two hundred eleven million, one hundred eleven thousand, one hundred eleven".