228133421 has 6 divisors (see below), whose sum is σ = 242342730. Its totient is φ = 214713536.

The previous prime is 228133417. The next prime is 228133463. The reversal of 228133421 is 124331822.

It can be written as a sum of positive squares in 3 ways, for example, as 98287396 + 129846025 = 9914^2 + 11395^2 .

It is not a de Polignac number, because 228133421 - 2² = 228133417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228133121) 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 5 ways as a sum of consecutive naturals, for example, 394406 + ... + 394983.

It is an arithmetic number, because the mean of its divisors is an integer number (40390455).

Almost surely, 2^228133421 is an apocalyptic number.

It is an amenable number.

228133421 is a deficient number, since it is larger than the sum of its proper divisors (14209309).

228133421 is an equidigital number, since it uses as much as digits as its factorization.

228133421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 789423 (or 789406 counting only the distinct ones).

The product of its digits is 2304, while the sum is 26.

The square root of 228133421 is about 15104.0862351881. The cubic root of 228133421 is about 611.0306155488.

The spelling of 228133421 in words is "two hundred twenty-eight million, one hundred thirty-three thousand, four hundred twenty-one".