221445553 has 12 divisors (see below), whose sum is σ = 272753892. Its totient is φ = 178644480.

The previous prime is 221445491. The next prime is 221445559. The reversal of 221445553 is 355544122.

It can be written as a sum of positive squares in 2 ways, for example, as 179881744 + 41563809 = 13412^2 + 6447^2 .

It is not a de Polignac number, because 221445553 - 2¹³ = 221437361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221445559) 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 11 ways as a sum of consecutive naturals, for example, 132088 + ... + 133753.

It is an arithmetic number, because the mean of its divisors is an integer number (22729491).

Almost surely, 2^221445553 is an apocalyptic number.

It is an amenable number.

221445553 is a deficient number, since it is larger than the sum of its proper divisors (51308339).

221445553 is a wasteful number, since it uses less digits than its factorization.

221445553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265872 (or 265865 counting only the distinct ones).

The product of its digits is 24000, while the sum is 31.

The square root of 221445553 is about 14881.0467709768. The cubic root of 221445553 is about 605.0003897728. Note that the first 3 decimals are identical.

Adding to 221445553 its reverse (355544122), we get a palindrome (576989675).

The spelling of 221445553 in words is "two hundred twenty-one million, four hundred forty-five thousand, five hundred fifty-three".