28297878 has 32 divisors (see below), whose sum is σ = 68087040. Its totient is φ = 7659360.

The previous prime is 28297873. The next prime is 28297891. The reversal of 28297878 is 87879282.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 28297878.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28297873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16933 + ... + 18528.

It is an arithmetic number, because the mean of its divisors is an integer number (2127720).

Almost surely, 2^28297878 is an apocalyptic number.

28297878 is an abundant number, since it is smaller than the sum of its proper divisors (39789162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28297878 is a wasteful number, since it uses less digits than its factorization.

28297878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35492.

The product of its digits is 903168, while the sum is 51.

The square root of 28297878 is about 5319.5749830226. The cubic root of 28297878 is about 304.7319260558.

The spelling of 28297878 in words is "twenty-eight million, two hundred ninety-seven thousand, eight hundred seventy-eight".