221280445 has 4 divisors (see below), whose sum is σ = 265536540. Its totient is φ = 177024352.

The previous prime is 221280439. The next prime is 221280457. The reversal of 221280445 is 544082122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 544082122 = 2 ⋅272041061.

It can be written as a sum of positive squares in 2 ways, for example, as 54715609 + 166564836 = 7397^2 + 12906^2 .

It is a cyclic number.

It is not a de Polignac number, because 221280445 - 2⁵ = 221280413 is a prime.

It is a congruent 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, 22128040 + ... + 22128049.

It is an arithmetic number, because the mean of its divisors is an integer number (66384135).

Almost surely, 2^221280445 is an apocalyptic number.

It is an amenable number.

221280445 is a deficient number, since it is larger than the sum of its proper divisors (44256095).

221280445 is an equidigital number, since it uses as much as digits as its factorization.

221280445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44256094.

The product of its (nonzero) digits is 5120, while the sum is 28.

The square root of 221280445 is about 14875.4981429194. The cubic root of 221280445 is about 604.8499912676.

The spelling of 221280445 in words is "two hundred twenty-one million, two hundred eighty thousand, four hundred forty-five".