231221113 has 2 divisors, whose sum is σ = 231221114. Its totient is φ = 231221112.

The previous prime is 231221083. The next prime is 231221117. The reversal of 231221113 is 311122132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120824064 + 110397049 = 10992^2 + 10507^2 .

It is a cyclic number.

It is not a de Polignac number, because 231221113 - 2¹³ = 231212921 is a prime.

It is not a weakly prime, because it can be changed into another prime (231221117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610556 + 115610557.

It is an arithmetic number, because the mean of its divisors is an integer number (115610557).

Almost surely, 2^231221113 is an apocalyptic number.

It is an amenable number.

231221113 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221113 is an equidigital number, since it uses as much as digits as its factorization.

231221113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 16.

The square root of 231221113 is about 15205.9564973730. The cubic root of 231221113 is about 613.7749540420.

Adding to 231221113 its reverse (311122132), we get a palindrome (542343245).

The spelling of 231221113 in words is "two hundred thirty-one million, two hundred twenty-one thousand, one hundred thirteen".