28705047 has 8 divisors (see below), whose sum is σ = 43741056. Its totient is φ = 16402872.

The previous prime is 28705021. The next prime is 28705049. The reversal of 28705047 is 74050782.

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

It is not a de Polignac number, because 28705047 - 2¹⁵ = 28672279 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28704999 and 28705017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28705049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 683433 + ... + 683474.

It is an arithmetic number, because the mean of its divisors is an integer number (5467632).

Almost surely, 2^28705047 is an apocalyptic number.

28705047 is a deficient number, since it is larger than the sum of its proper divisors (15036009).

28705047 is a wasteful number, since it uses less digits than its factorization.

28705047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1366917.

The product of its (nonzero) digits is 15680, while the sum is 33.

The square root of 28705047 is about 5357.7091186439. The cubic root of 28705047 is about 306.1865345649.

The spelling of 28705047 in words is "twenty-eight million, seven hundred five thousand, forty-seven".