28133447 has 4 divisors (see below), whose sum is σ = 28194936. Its totient is φ = 28071960.

The previous prime is 28133437. The next prime is 28133459. The reversal of 28133447 is 74433182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74433182 = 2 ⋅37216591.

It is a cyclic number.

It is not a de Polignac number, because 28133447 - 2⁸ = 28133191 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 (28133437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30053 + ... + 30974.

It is an arithmetic number, because the mean of its divisors is an integer number (7048734).

Almost surely, 2^28133447 is an apocalyptic number.

28133447 is a deficient number, since it is larger than the sum of its proper divisors (61489).

28133447 is an equidigital number, since it uses as much as digits as its factorization.

28133447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61488.

The product of its digits is 16128, while the sum is 32.

The square root of 28133447 is about 5304.0971899089. The cubic root of 28133447 is about 304.1405419817.

The spelling of 28133447 in words is "twenty-eight million, one hundred thirty-three thousand, four hundred forty-seven".