228772221 has 24 divisors (see below), whose sum is σ = 319715424. Its totient is φ = 145454400.

The previous prime is 228772207. The next prime is 228772223. The reversal of 228772221 is 122277822.

It is not a de Polignac number, because 228772221 - 2⁹ = 228771709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228772223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 217146 + ... + 218196.

It is an arithmetic number, because the mean of its divisors is an integer number (13321476).

Almost surely, 2^228772221 is an apocalyptic number.

It is an amenable number.

228772221 is a deficient number, since it is larger than the sum of its proper divisors (90943203).

228772221 is a wasteful number, since it uses less digits than its factorization.

228772221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181 (or 1144 counting only the distinct ones).

The product of its digits is 12544, while the sum is 33.

The square root of 228772221 is about 15125.2180480150. The cubic root of 228772221 is about 611.6004028857.

The spelling of 228772221 in words is "two hundred twenty-eight million, seven hundred seventy-two thousand, two hundred twenty-one".