228544222445821 has 4 divisors (see below), whose sum is σ = 228544369084444. Its totient is φ = 228544075807200.

The previous prime is 228544222445789. The next prime is 228544222445831. The reversal of 228544222445821 is 128544222445822.

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

It can be written as a sum of positive squares in 2 ways, for example, as 187307417160900 + 41236805284921 = 13686030^2 + 6421589^2 .

It is a cyclic number.

It is not a de Polignac number, because 228544222445821 - 2⁵ = 228544222445789 is a prime.

It is a super-2 number, since 2×228544222445821² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228544222445831) 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, 70956090 + ... + 74107051.

It is an arithmetic number, because the mean of its divisors is an integer number (57136092271111).

Almost surely, 2^{228544222445821} is an apocalyptic number.

It is an amenable number.

228544222445821 is a deficient number, since it is larger than the sum of its proper divisors (146638623).

228544222445821 is a wasteful number, since it uses less digits than its factorization.

228544222445821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146638622.

The product of its digits is 26214400, while the sum is 55.

Subtracting from 228544222445821 its reverse (128544222445822), we obtain a palindrome (99999999999999).

The spelling of 228544222445821 in words is "two hundred twenty-eight trillion, five hundred forty-four billion, two hundred twenty-two million, four hundred forty-five thousand, eight hundred twenty-one".