28009903 has 2 divisors, whose sum is σ = 28009904. Its totient is φ = 28009902.

The previous prime is 28009901. The next prime is 28009907. The reversal of 28009903 is 30990082.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28009903 - 2¹ = 28009901 is a prime.

Together with 28009901, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28009901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14004951 + 14004952.

It is an arithmetic number, because the mean of its divisors is an integer number (14004952).

Almost surely, 2^28009903 is an apocalyptic number.

28009903 is a deficient number, since it is larger than the sum of its proper divisors (1).

28009903 is an equidigital number, since it uses as much as digits as its factorization.

28009903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 28009903 is about 5292.4382849496. The cubic root of 28009903 is about 303.6946921829.

Adding to 28009903 its reverse (30990082), we get a palindrome (58999985).

The spelling of 28009903 in words is "twenty-eight million, nine thousand, nine hundred three".