221424553 has 4 divisors (see below), whose sum is σ = 253056640. Its totient is φ = 189792468.

The previous prime is 221424551. The next prime is 221424557. The reversal of 221424553 is 355424122.

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 221424553 - 2¹ = 221424551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221424551) 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, 15816033 + ... + 15816046.

It is an arithmetic number, because the mean of its divisors is an integer number (63264160).

Almost surely, 2^221424553 is an apocalyptic number.

It is an amenable number.

221424553 is a deficient number, since it is larger than the sum of its proper divisors (31632087).

221424553 is an equidigital number, since it uses as much as digits as its factorization.

221424553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31632086.

The product of its digits is 9600, while the sum is 28.

The square root of 221424553 is about 14880.3411587235. The cubic root of 221424553 is about 604.9812648161.

Adding to 221424553 its reverse (355424122), we get a palindrome (576848675).

The spelling of 221424553 in words is "two hundred twenty-one million, four hundred twenty-four thousand, five hundred fifty-three".