231241221 has 12 divisors (see below), whose sum is σ = 334407372. Its totient is φ = 153979776.

The previous prime is 231241207. The next prime is 231241247. The reversal of 231241221 is 122142132.

It is a happy number.

231241221 is a `hidden beast` number, since 231 + 2 + 412 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 179184996 + 52056225 = 13386^2 + 7215^2 .

It is not a de Polignac number, because 231241221 - 2⁷ = 231241093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231241194 and 231241203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231241291) 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 in 11 ways as a sum of consecutive naturals, for example, 6756 + ... + 22541.

It is an arithmetic number, because the mean of its divisors is an integer number (27867281).

Almost surely, 2^231241221 is an apocalyptic number.

It is an amenable number.

231241221 is a deficient number, since it is larger than the sum of its proper divisors (103166151).

231241221 is a wasteful number, since it uses less digits than its factorization.

231241221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30180 (or 30177 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 231241221 is about 15206.6176712640. The cubic root of 231241221 is about 613.7927457117.

Adding to 231241221 its reverse (122142132), we get a palindrome (353383353).

The spelling of 231241221 in words is "two hundred thirty-one million, two hundred forty-one thousand, two hundred twenty-one".