28705918 has 4 divisors (see below), whose sum is σ = 43058880. Its totient is φ = 14352958.

The previous prime is 28705891. The next prime is 28705921. The reversal of 28705918 is 81950782.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 7176478 + ... + 7176481.

It is an arithmetic number, because the mean of its divisors is an integer number (10764720).

Almost surely, 2^28705918 is an apocalyptic number.

28705918 is a deficient number, since it is larger than the sum of its proper divisors (14352962).

28705918 is a wasteful number, since it uses less digits than its factorization.

28705918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14352961.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 28705918 is about 5357.7904027687. The cubic root of 28705918 is about 306.1896314161.

The spelling of 28705918 in words is "twenty-eight million, seven hundred five thousand, nine hundred eighteen".