228128305 has 8 divisors (see below), whose sum is σ = 280431144. Its totient is φ = 178051200.

The previous prime is 228128293. The next prime is 228128309. The reversal of 228128305 is 503821822.

It can be written as a sum of positive squares in 4 ways, for example, as 1083681 + 227044624 = 1041^2 + 15068^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 228128305 - 2⁹ = 228127793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (228128309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 556206 + ... + 556615.

It is an arithmetic number, because the mean of its divisors is an integer number (35053893).

Almost surely, 2^228128305 is an apocalyptic number.

It is an amenable number.

228128305 is a deficient number, since it is larger than the sum of its proper divisors (52302839).

228128305 is a wasteful number, since it uses less digits than its factorization.

228128305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112867.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 228128305 is about 15103.9168760954. The cubic root of 228128305 is about 611.0260479644.

The spelling of 228128305 in words is "two hundred twenty-eight million, one hundred twenty-eight thousand, three hundred five".