28078247 has 4 divisors (see below), whose sum is σ = 28091136. Its totient is φ = 28065360.

The previous prime is 28078243. The next prime is 28078261. The reversal of 28078247 is 74287082.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28078247 - 2² = 28078243 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28078247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28078243) 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 3 ways as a sum of consecutive naturals, for example, 2279 + ... + 7832.

It is an arithmetic number, because the mean of its divisors is an integer number (7022784).

Almost surely, 2^28078247 is an apocalyptic number.

28078247 is a deficient number, since it is larger than the sum of its proper divisors (12889).

28078247 is a wasteful number, since it uses less digits than its factorization.

28078247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12888.

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 28078247 is about 5298.8911104117. The cubic root of 28078247 is about 303.9414959844.

The spelling of 28078247 in words is "twenty-eight million, seventy-eight thousand, two hundred forty-seven".