221423231 has 4 divisors (see below), whose sum is σ = 231050352. Its totient is φ = 211796112.

The previous prime is 221423203. The next prime is 221423243. The reversal of 221423231 is 132324122.

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

It is a cyclic number.

It is not a de Polignac number, because 221423231 - 2¹⁰ = 221422207 is a prime.

It is a super-2 number, since 2×221423231² = 98056494452958722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221423431) 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 3 ways as a sum of consecutive naturals, for example, 4813526 + ... + 4813571.

It is an arithmetic number, because the mean of its divisors is an integer number (57762588).

Almost surely, 2^221423231 is an apocalyptic number.

221423231 is a deficient number, since it is larger than the sum of its proper divisors (9627121).

221423231 is an equidigital number, since it uses as much as digits as its factorization.

221423231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9627120.

The product of its digits is 576, while the sum is 20.

The square root of 221423231 is about 14880.2967376326. The cubic root of 221423231 is about 604.9800608141.

Adding to 221423231 its reverse (132324122), we get a palindrome (353747353).

The spelling of 221423231 in words is "two hundred twenty-one million, four hundred twenty-three thousand, two hundred thirty-one".