1121 has 4 divisors (see below), whose sum is σ = 1200. Its totient is φ = 1044.

The previous prime is 1117. The next prime is 1123. The reversal of 1121 is 1211.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1211 = 7 ⋅173.

It is a cyclic number.

It is not a de Polignac number, because 1121 - 2^{2} = 1117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1123) 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, 11 + ... + 48.

It is an arithmetic number, because the mean of its divisors is an integer number (300).

It is an amenable number.

1121 is a deficient number, since it is larger than the sum of its proper divisors (79).

1121 is an equidigital number, since it uses as much as digits as its factorization.

1121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78.

The product of its digits is 2, while the sum is 5.

The square root of 1121 is about 33.4813380856. The cubic root of 1121 is about 10.3880780546.

Adding to 1121 its reverse (1211), we get a palindrome (2332).

Multiplying 1121 by its reverse (1211), we get a palindrome (1357531).

It can be divided in two parts, 11 and 21, that multiplied together give a triangular number (231 = T_{21}).

The spelling of 1121 in words is "one thousand, one hundred twenty-one", and thus it is an iban number.

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