28668947 has 8 divisors (see below), whose sum is σ = 29347920. Its totient is φ = 27998080.

The previous prime is 28668931. The next prime is 28668949. The reversal of 28668947 is 74986682.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28668947 - 2⁴ = 28668931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28668895 and 28668904.

It is not an unprimeable number, because it can be changed into a prime (28668949) 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 7 ways as a sum of consecutive naturals, for example, 5447 + ... + 9327.

It is an arithmetic number, because the mean of its divisors is an integer number (3668490).

Almost surely, 2^28668947 is an apocalyptic number.

28668947 is a deficient number, since it is larger than the sum of its proper divisors (678973).

28668947 is an equidigital number, since it uses as much as digits as its factorization.

28668947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4053.

The product of its digits is 1161216, while the sum is 50.

The square root of 28668947 is about 5354.3390815300. The cubic root of 28668947 is about 306.0581254300.

The spelling of 28668947 in words is "twenty-eight million, six hundred sixty-eight thousand, nine hundred forty-seven".