1113121021 has 2 divisors, whose sum is σ = 1113121022. Its totient is φ = 1113121020.

The previous prime is 1113121003. The next prime is 1113121033. The reversal of 1113121021 is 1201213111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1031308996 + 81812025 = 32114^2 + 9045^2 .

It is a cyclic number.

It is not a de Polignac number, because 1113121021 - 2⁵ = 1113120989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1113120992 and 1113121010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1113121421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 556560510 + 556560511.

It is an arithmetic number, because the mean of its divisors is an integer number (556560511).

Almost surely, 2^1113121021 is an apocalyptic number.

It is an amenable number.

1113121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1113121021 is an equidigital number, since it uses as much as digits as its factorization.

1113121021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1113121021 is about 33363.4683598693. The cubic root of 1113121021 is about 1036.3683181912.

Adding to 1113121021 its reverse (1201213111), we get a palindrome (2314334132).

The spelling of 1113121021 in words is "one billion, one hundred thirteen million, one hundred twenty-one thousand, twenty-one".