221330231 has 2 divisors, whose sum is σ = 221330232. Its totient is φ = 221330230.

The previous prime is 221330201. The next prime is 221330243. The reversal of 221330231 is 132033122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221330231 - 2⁶ = 221330167 is a prime.

It is a super-2 number, since 2×221330231² = 97974142309026722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221330201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110665115 + 110665116.

It is an arithmetic number, because the mean of its divisors is an integer number (110665116).

Almost surely, 2^221330231 is an apocalyptic number.

221330231 is a deficient number, since it is larger than the sum of its proper divisors (1).

221330231 is an equidigital number, since it uses as much as digits as its factorization.

221330231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 221330231 is about 14877.1714717550. The cubic root of 221330231 is about 604.8953497018.

Adding to 221330231 its reverse (132033122), we get a palindrome (353363353).

The spelling of 221330231 in words is "two hundred twenty-one million, three hundred thirty thousand, two hundred thirty-one".