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28030221 = 3213272347
BaseRepresentation
bin110101011101…
…1010100001101
31221202002020100
41222323110031
524133431341
62440441313
7460152522
oct152732415
957662210
1028030221
111490557a
129479239
135a6553b
143a19149
1526da3b6
hex1abb50d

28030221 has 12 divisors (see below), whose sum is σ = 40535872. Its totient is φ = 18664776.

The previous prime is 28030217. The next prime is 28030237. The reversal of 28030221 is 12203082.

It is a happy number.

It is not a de Polignac number, because 28030221 - 22 = 28030217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28030194 and 28030203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28030241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10770 + ... + 13116.

Almost surely, 228030221 is an apocalyptic number.

It is an amenable number.

28030221 is a deficient number, since it is larger than the sum of its proper divisors (12505651).

28030221 is a wasteful number, since it uses less digits than its factorization.

28030221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3680 (or 3677 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 28030221 is about 5294.3574680975. The cubic root of 28030221 is about 303.7681064246.

The spelling of 28030221 in words is "twenty-eight million, thirty thousand, two hundred twenty-one".

Divisors: 1 3 9 1327 2347 3981 7041 11943 21123 3114469 9343407 28030221