11123220121 has 4 divisors (see below), whose sum is σ = 11978852452. Its totient is φ = 10267587792.

The previous prime is 11123220029. The next prime is 11123220133. The reversal of 11123220121 is 12102232111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12102232111 = 107 ⋅113104973.

It can be written as a sum of positive squares in 2 ways, for example, as 4697594521 + 6425625600 = 68539^2 + 80160^2 .

It is a cyclic number.

It is not a de Polignac number, because 11123220121 - 2⁷ = 11123219993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11123220095 and 11123220104.

It is not an unprimeable number, because it can be changed into a prime (11123220191) 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, 427816146 + ... + 427816171.

It is an arithmetic number, because the mean of its divisors is an integer number (2994713113).

Almost surely, 2^11123220121 is an apocalyptic number.

It is an amenable number.

11123220121 is a deficient number, since it is larger than the sum of its proper divisors (855632331).

11123220121 is an equidigital number, since it uses as much as digits as its factorization.

11123220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855632330.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 11123220121 its reverse (12102232111), we get a palindrome (23225452232).

The spelling of 11123220121 in words is "eleven billion, one hundred twenty-three million, two hundred twenty thousand, one hundred twenty-one".