11123122121 has 4 divisors (see below), whose sum is σ = 11481932544. Its totient is φ = 10764311700.

The previous prime is 11123122039. The next prime is 11123122141. The reversal of 11123122121 is 12122132111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12122132111 = 6203 ⋅1954237.

It is a cyclic number.

It is not a de Polignac number, because 11123122121 - 2²² = 11118927817 is a prime.

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 11123122121.

It is not an unprimeable number, because it can be changed into a prime (11123122141) 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, 179405165 + ... + 179405226.

It is an arithmetic number, because the mean of its divisors is an integer number (2870483136).

Almost surely, 2^11123122121 is an apocalyptic number.

It is an amenable number.

11123122121 is a deficient number, since it is larger than the sum of its proper divisors (358810423).

11123122121 is an equidigital number, since it uses as much as digits as its factorization.

11123122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358810422.

The product of its digits is 48, while the sum is 17.

Adding to 11123122121 its reverse (12122132111), we get a palindrome (23245254232).

The spelling of 11123122121 in words is "eleven billion, one hundred twenty-three million, one hundred twenty-two thousand, one hundred twenty-one".