231133221 has 12 divisors (see below), whose sum is σ = 364210080. Its totient is φ = 140080680.

The previous prime is 231133211. The next prime is 231133237. The reversal of 231133221 is 122331132.

231133221 is a `hidden beast` number, since 2 + 311 + 332 + 21 = 666.

It is not a de Polignac number, because 231133221 - 2⁷ = 231133093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231133194 and 231133203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231133211) 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, 1167241 + ... + 1167438.

It is an arithmetic number, because the mean of its divisors is an integer number (30350840).

Almost surely, 2^231133221 is an apocalyptic number.

It is an amenable number.

231133221 is a deficient number, since it is larger than the sum of its proper divisors (133076859).

231133221 is a wasteful number, since it uses less digits than its factorization.

231133221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2334696 (or 2334693 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 231133221 is about 15203.0661710064. The cubic root of 231133221 is about 613.6971746035.

Adding to 231133221 its reverse (122331132), we get a palindrome (353464353).

The spelling of 231133221 in words is "two hundred thirty-one million, one hundred thirty-three thousand, two hundred twenty-one".