221540233 has 4 divisors (see below), whose sum is σ = 221775120. Its totient is φ = 221305348.

The previous prime is 221540219. The next prime is 221540269. The reversal of 221540233 is 332045122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221540233 - 2¹³ = 221532041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221540213) 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, 116023 + ... + 117916.

It is an arithmetic number, because the mean of its divisors is an integer number (55443780).

Almost surely, 2^221540233 is an apocalyptic number.

It is an amenable number.

221540233 is a deficient number, since it is larger than the sum of its proper divisors (234887).

221540233 is an equidigital number, since it uses as much as digits as its factorization.

221540233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234886.

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 221540233 is about 14884.2276588340. The cubic root of 221540233 is about 605.0866009948.

Adding to 221540233 its reverse (332045122), we get a palindrome (553585355).

The spelling of 221540233 in words is "two hundred twenty-one million, five hundred forty thousand, two hundred thirty-three".