231221163 has 4 divisors (see below), whose sum is σ = 308294888. Its totient is φ = 154147440.

The previous prime is 231221129. The next prime is 231221167. The reversal of 231221163 is 361122132.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 231221163 - 2⁸ = 231220907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231221167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38536858 + ... + 38536863.

It is an arithmetic number, because the mean of its divisors is an integer number (77073722).

Almost surely, 2^231221163 is an apocalyptic number.

231221163 is a deficient number, since it is larger than the sum of its proper divisors (77073725).

231221163 is an equidigital number, since it uses as much as digits as its factorization.

231221163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77073724.

The product of its digits is 432, while the sum is 21.

The square root of 231221163 is about 15205.9581414655. The cubic root of 231221163 is about 613.7749982836.

Adding to 231221163 its reverse (361122132), we get a palindrome (592343295).

The spelling of 231221163 in words is "two hundred thirty-one million, two hundred twenty-one thousand, one hundred sixty-three".