28857907 has 4 divisors (see below), whose sum is σ = 31077760. Its totient is φ = 26638056.

The previous prime is 28857889. The next prime is 28857911. The reversal of 28857907 is 70975882.

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 28857907 - 2⁷ = 28857779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28857937) 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, 1109907 + ... + 1109932.

It is an arithmetic number, because the mean of its divisors is an integer number (7769440).

Almost surely, 2^28857907 is an apocalyptic number.

28857907 is the 3102-nd hex number.

28857907 is a deficient number, since it is larger than the sum of its proper divisors (2219853).

28857907 is a wasteful number, since it uses less digits than its factorization.

28857907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2219852.

The product of its (nonzero) digits is 282240, while the sum is 46.

The square root of 28857907 is about 5371.9556029439. The cubic root of 28857907 is about 306.7290737569.

The spelling of 28857907 in words is "twenty-eight million, eight hundred fifty-seven thousand, nine hundred seven".