28228628 has 6 divisors (see below), whose sum is σ = 49400106. Its totient is φ = 14114312.

The previous prime is 28228621. The next prime is 28228639. The reversal of 28228628 is 82682282.

It can be written as a sum of positive squares in only one way, i.e., 26234884 + 1993744 = 5122^2 + 1412^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28228591 and 28228600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28228621) 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 as a sum of consecutive naturals, namely, 3528575 + ... + 3528582.

It is an arithmetic number, because the mean of its divisors is an integer number (8233351).

Almost surely, 2^28228628 is an apocalyptic number.

It is an amenable number.

28228628 is a deficient number, since it is larger than the sum of its proper divisors (21171478).

28228628 is a wasteful number, since it uses less digits than its factorization.

28228628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7057161 (or 7057159 counting only the distinct ones).

The product of its digits is 49152, while the sum is 38.

The square root of 28228628 is about 5313.0620173305. The cubic root of 28228628 is about 304.4831450537.

The spelling of 28228628 in words is "twenty-eight million, two hundred twenty-eight thousand, six hundred twenty-eight".