1211103121 has 4 divisors (see below), whose sum is σ = 1213632000. Its totient is φ = 1208574244.

The previous prime is 1211103043. The next prime is 1211103139. The reversal of 1211103121 is 1213011121.

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.

It is a cyclic number.

It is not a de Polignac number, because 1211103121 - 2⁷ = 1211102993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211103521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1263721 + ... + 1264678.

It is an arithmetic number, because the mean of its divisors is an integer number (303408000).

Almost surely, 2^1211103121 is an apocalyptic number.

It is an amenable number.

1211103121 is a deficient number, since it is larger than the sum of its proper divisors (2528879).

1211103121 is an equidigital number, since it uses as much as digits as its factorization.

1211103121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528878.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1211103121 is about 34800.9068991025. The cubic root of 1211103121 is about 1065.9259643607.

Adding to 1211103121 its reverse (1213011121), we get a palindrome (2424114242).

The spelling of 1211103121 in words is "one billion, two hundred eleven million, one hundred three thousand, one hundred twenty-one".