28385857 has 4 divisors (see below), whose sum is σ = 28408576. Its totient is φ = 28363140.

The previous prime is 28385843. The next prime is 28385881. The reversal of 28385857 is 75858382.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75858382 = 2 ⋅37929191.

It is a cyclic number.

It is not a de Polignac number, because 28385857 - 2¹⁹ = 27861569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28385837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9369 + ... + 12022.

It is an arithmetic number, because the mean of its divisors is an integer number (7102144).

Almost surely, 2^28385857 is an apocalyptic number.

It is an amenable number.

28385857 is a deficient number, since it is larger than the sum of its proper divisors (22719).

28385857 is a wasteful number, since it uses less digits than its factorization.

28385857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22718.

The product of its digits is 537600, while the sum is 46.

The square root of 28385857 is about 5327.8379292167. The cubic root of 28385857 is about 305.0474064089.

The spelling of 28385857 in words is "twenty-eight million, three hundred eighty-five thousand, eight hundred fifty-seven".