231228121 has 2 divisors, whose sum is σ = 231228122. Its totient is φ = 231228120.

The previous prime is 231228113. The next prime is 231228143. The reversal of 231228121 is 121822132.

It is an a-pointer prime, because the next prime (231228143) can be obtained adding 231228121 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214212496 + 17015625 = 14636^2 + 4125^2 .

It is a cyclic number.

It is not a de Polignac number, because 231228121 - 2³ = 231228113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231228092 and 231228101.

It is not a weakly prime, because it can be changed into another prime (231228161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115614060 + 115614061.

It is an arithmetic number, because the mean of its divisors is an integer number (115614061).

Almost surely, 2^231228121 is an apocalyptic number.

It is an amenable number.

231228121 is a deficient number, since it is larger than the sum of its proper divisors (1).

231228121 is an equidigital number, since it uses as much as digits as its factorization.

231228121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 22.

The square root of 231228121 is about 15206.1869316407. The cubic root of 231228121 is about 613.7811548763.

The spelling of 231228121 in words is "two hundred thirty-one million, two hundred twenty-eight thousand, one hundred twenty-one".