1211211111121 has 8 divisors (see below), whose sum is σ = 1329737272704. Its totient is φ = 1094087626320.

The previous prime is 1211211111091. The next prime is 1211211111197. The reversal of 1211211111121 is 1211111121121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211211111121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211211111095 and 1211211111104.

It is not an unprimeable number, because it can be changed into a prime (1211211111221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350667385 + ... + 350670838.

It is an arithmetic number, because the mean of its divisors is an integer number (166217159088).

Almost surely, 2^{1211211111121} is an apocalyptic number.

1211211111121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211211111121 is a deficient number, since it is larger than the sum of its proper divisors (118526161583).

1211211111121 is a wasteful number, since it uses less digits than its factorization.

1211211111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701338391.

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

Adding to 1211211111121 its reverse (1211111121121), we get a palindrome (2422322232242).

It can be divided in two parts, 121 and 1211111121, that multiplied together give a palindrome (146544445641).

The spelling of 1211211111121 in words is "one trillion, two hundred eleven billion, two hundred eleven million, one hundred eleven thousand, one hundred twenty-one".