221330555 has 4 divisors (see below), whose sum is σ = 265596672. Its totient is φ = 177064440.

The previous prime is 221330533. The next prime is 221330569. The reversal of 221330555 is 555033122.

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

It is not a de Polignac number, because 221330555 - 2¹⁰ = 221329531 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22133051 + ... + 22133060.

It is an arithmetic number, because the mean of its divisors is an integer number (66399168).

Almost surely, 2^221330555 is an apocalyptic number.

221330555 is a deficient number, since it is larger than the sum of its proper divisors (44266117).

221330555 is an equidigital number, since it uses as much as digits as its factorization.

221330555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44266116.

The product of its (nonzero) digits is 4500, while the sum is 26.

The square root of 221330555 is about 14877.1823609177. The cubic root of 221330555 is about 604.8956448656.

Adding to 221330555 its reverse (555033122), we get a palindrome (776363677).

It can be divided in two parts, 2213 and 30555, that added together give a 15-th power (32768 = 2¹⁵).

The spelling of 221330555 in words is "two hundred twenty-one million, three hundred thirty thousand, five hundred fifty-five".