28978815 has 8 divisors (see below), whose sum is σ = 46366128. Its totient is φ = 15455360.

The previous prime is 28978813. The next prime is 28978823. The reversal of 28978815 is 51887982.

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

It is not a de Polignac number, because 28978815 - 2¹ = 28978813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28978813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 965946 + ... + 965975.

It is an arithmetic number, because the mean of its divisors is an integer number (5795766).

Almost surely, 2^28978815 is an apocalyptic number.

28978815 is a deficient number, since it is larger than the sum of its proper divisors (17387313).

28978815 is a wasteful number, since it uses less digits than its factorization.

28978815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1931929.

The product of its digits is 322560, while the sum is 48.

The square root of 28978815 is about 5383.1974699058. The cubic root of 28978815 is about 307.1568516635.

The spelling of 28978815 in words is "twenty-eight million, nine hundred seventy-eight thousand, eight hundred fifteen".