28643903 has 8 divisors (see below), whose sum is σ = 29478816. Its totient is φ = 27820000.

The previous prime is 28643897. The next prime is 28643917. The reversal of 28643903 is 30934682.

It is a happy number.

It is a Cunningham number, because it is equal to 5352²-1.

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

It is a cyclic number.

It is not a de Polignac number, because 28643903 - 2⁸ = 28643647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28643933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2678 + ... + 8028.

It is an arithmetic number, because the mean of its divisors is an integer number (3684852).

Almost surely, 2^28643903 is an apocalyptic number.

28643903 is a deficient number, since it is larger than the sum of its proper divisors (834913).

28643903 is a wasteful number, since it uses less digits than its factorization.

28643903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5505.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 28643903 is about 5351.9999065770. Note that the first 4 decimals coincide. The cubic root of 28643903 is about 305.9689795829.

The spelling of 28643903 in words is "twenty-eight million, six hundred forty-three thousand, nine hundred three".