28133289 has 6 divisors (see below), whose sum is σ = 40636986. Its totient is φ = 18755520.

The previous prime is 28133267. The next prime is 28133291. The reversal of 28133289 is 98233182.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 27123264 + 1010025 = 5208^2 + 1005^2 .

It is not a de Polignac number, because 28133289 - 2⁸ = 28133033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28133299) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1562952 + ... + 1562969.

It is an arithmetic number, because the mean of its divisors is an integer number (6772831).

Almost surely, 2^28133289 is an apocalyptic number.

It is an amenable number.

28133289 is a deficient number, since it is larger than the sum of its proper divisors (12503697).

28133289 is a wasteful number, since it uses less digits than its factorization.

28133289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3125927 (or 3125924 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 28133289 is about 5304.0822957416. The cubic root of 28133289 is about 304.1399726204.

The spelling of 28133289 in words is "twenty-eight million, one hundred thirty-three thousand, two hundred eighty-nine".