1121211211111 has 4 divisors (see below), whose sum is σ = 1121247991800. Its totient is φ = 1121174430424.

The previous prime is 1121211211097. The next prime is 1121211211171. The reversal of 1121211211111 is 1111121121211.

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 1121211211111 - 2²⁵ = 1121177656679 is a prime.

It is a super-2 number, since 2×1121211211111² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121211211171) 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, 18344581 + ... + 18405598.

It is an arithmetic number, because the mean of its divisors is an integer number (280311997950).

Almost surely, 2^{1121211211111} is an apocalyptic number.

1121211211111 is a deficient number, since it is larger than the sum of its proper divisors (36780689).

1121211211111 is an equidigital number, since it uses as much as digits as its factorization.

1121211211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36780688.

The product of its digits is 8, while the sum is 16.

Adding to 1121211211111 its reverse (1111121121211), we get a palindrome (2232332332322).

The spelling of 1121211211111 in words is "one trillion, one hundred twenty-one billion, two hundred eleven million, two hundred eleven thousand, one hundred eleven".