111111211020121 has 4 divisors (see below), whose sum is σ = 119658227252452. Its totient is φ = 102564194787792.

The previous prime is 111111211020113. The next prime is 111111211020163. The reversal of 111111211020121 is 121020112111111.

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

It can be written as a sum of positive squares in 2 ways, for example, as 56533631643225 + 54577579376896 = 7518885^2 + 7387664^2 .

It is a cyclic number.

It is not a de Polignac number, because 111111211020121 - 2³ = 111111211020113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111111211020095 and 111111211020104.

It is not an unprimeable number, because it can be changed into a prime (111111211020521) 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, 4273508116146 + ... + 4273508116171.

It is an arithmetic number, because the mean of its divisors is an integer number (29914556813113).

Almost surely, 2^{111111211020121} is an apocalyptic number.

It is an amenable number.

111111211020121 is a deficient number, since it is larger than the sum of its proper divisors (8547016232331).

111111211020121 is an equidigital number, since it uses as much as digits as its factorization.

111111211020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8547016232330.

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

Adding to 111111211020121 its reverse (121020112111111), we get a palindrome (232131323131232).

The spelling of 111111211020121 in words is "one hundred eleven trillion, one hundred eleven billion, two hundred eleven million, twenty thousand, one hundred twenty-one".