1121212121111 has 16 divisors (see below), whose sum is σ = 1253109944160. Its totient is φ = 999718443648.

The previous prime is 1121212121041. The next prime is 1121212121143. The reversal of 1121212121111 is 1111212121211.

It is a de Polignac number, because none of the positive numbers 2^k-1121212121111 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1121212121111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121212121191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4691216 + ... + 4924421.

It is an arithmetic number, because the mean of its divisors is an integer number (78319371510).

Almost surely, 2^{1121212121111} is an apocalyptic number.

1121212121111 is a deficient number, since it is larger than the sum of its proper divisors (131897823049).

1121212121111 is an frugal number, since it uses more digits than its factorization.

1121212121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9615711 (or 9615673 counting only the distinct ones).

The product of its digits is 16, while the sum is 17.

Adding to 1121212121111 its reverse (1111212121211), we get a palindrome (2232424242322).

It can be divided in two parts, 11212121211 and 11, that multiplied together give a palindrome (123333333321).

The spelling of 1121212121111 in words is "one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, one hundred eleven".