228145221 has 16 divisors (see below), whose sum is σ = 342625920. Its totient is φ = 150012000.

The previous prime is 228145193. The next prime is 228145259. The reversal of 228145221 is 122541822.

It is not a de Polignac number, because 228145221 - 2¹⁹ = 227620933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228145121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55905 + ... + 59846.

It is an arithmetic number, because the mean of its divisors is an integer number (21414120).

Almost surely, 2^228145221 is an apocalyptic number.

It is an amenable number.

228145221 is a deficient number, since it is larger than the sum of its proper divisors (114480699).

228145221 is a wasteful number, since it uses less digits than its factorization.

228145221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115833 (or 115827 counting only the distinct ones).

The product of its digits is 2560, while the sum is 27.

The square root of 228145221 is about 15104.4768529069. The cubic root of 228145221 is about 611.0411503737.

The spelling of 228145221 in words is "two hundred twenty-eight million, one hundred forty-five thousand, two hundred twenty-one".