221331231 has 32 divisors (see below), whose sum is σ = 373271040. Its totient is φ = 128304000.

The previous prime is 221331199. The next prime is 221331251. The reversal of 221331231 is 132133122.

It is not a de Polignac number, because 221331231 - 2⁵ = 221331199 is a prime.

It is a super-2 number, since 2×221331231² = 97975027631950722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221331251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9370 + ... + 23031.

It is an arithmetic number, because the mean of its divisors is an integer number (11664720).

Almost surely, 2^221331231 is an apocalyptic number.

221331231 is a deficient number, since it is larger than the sum of its proper divisors (151939809).

221331231 is a wasteful number, since it uses less digits than its factorization.

221331231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32444 (or 32438 counting only the distinct ones).

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

The square root of 221331231 is about 14877.2050802562. The cubic root of 221331231 is about 604.8962607002.

Adding to 221331231 its reverse (132133122), we get a palindrome (353464353).

The spelling of 221331231 in words is "two hundred twenty-one million, three hundred thirty-one thousand, two hundred thirty-one".