228147021 has 12 divisors (see below), whose sum is σ = 348930972. Its totient is φ = 143150976.

The previous prime is 228147019. The next prime is 228147067. The reversal of 228147021 is 120741822.

It can be written as a sum of positive squares in 2 ways, for example, as 83064996 + 145082025 = 9114^2 + 12045^2 .

It is not a de Polignac number, because 228147021 - 2¹ = 228147019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228147091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 745426 + ... + 745731.

It is an arithmetic number, because the mean of its divisors is an integer number (29077581).

Almost surely, 2^228147021 is an apocalyptic number.

It is an amenable number.

228147021 is a deficient number, since it is larger than the sum of its proper divisors (120783951).

228147021 is a wasteful number, since it uses less digits than its factorization.

228147021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1491180 (or 1491177 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 228147021 is about 15104.5364377726. The cubic root of 228147021 is about 611.0427573490.

Adding to 228147021 its reverse (120741822), we get a palindrome (348888843).

The spelling of 228147021 in words is "two hundred twenty-eight million, one hundred forty-seven thousand, twenty-one".