11111121 has 16 divisors (see below), whose sum is σ = 18812800. Its totient is φ = 6349104.

The previous prime is 11111119. The next prime is 11111131. The reversal of 11111121 is 12111111.

11111121 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11111121 - 2¹ = 11111119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11111101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29206 + ... + 29583.

It is an arithmetic number, because the mean of its divisors is an integer number (1175800).

Almost surely, 2^11111121 is an apocalyptic number.

It is an amenable number.

11111121 is a deficient number, since it is larger than the sum of its proper divisors (7701679).

11111121 is an equidigital number, since it uses as much as digits as its factorization.

11111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58805 (or 58799 counting only the distinct ones).

The product of its digits is 2, while the sum is 9.

The square root of 11111121 is about 3333.3348166663. The cubic root of 11111121 is about 223.1443828935.

Adding to 11111121 its reverse (12111111), we get a palindrome (23222232).

It can be divided in two parts, 11111 and 121, that multiplied together give a palindrome (1344431).

The spelling of 11111121 in words is "eleven million, one hundred eleven thousand, one hundred twenty-one".