28278755 has 8 divisors (see below), whose sum is σ = 33963072. Its totient is φ = 22603968.

The previous prime is 28278751. The next prime is 28278763. The reversal of 28278755 is 55787282.

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 28278755 - 2² = 28278751 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28278751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10199 + ... + 12671.

It is an arithmetic number, because the mean of its divisors is an integer number (4245384).

Almost surely, 2^28278755 is an apocalyptic number.

28278755 is a deficient number, since it is larger than the sum of its proper divisors (5684317).

28278755 is a wasteful number, since it uses less digits than its factorization.

28278755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4765.

The product of its digits is 313600, while the sum is 44.

The square root of 28278755 is about 5317.7772612248. Note that the first 3 decimals coincide. The cubic root of 28278755 is about 304.6632671764.

The spelling of 28278755 in words is "twenty-eight million, two hundred seventy-eight thousand, seven hundred fifty-five".