28089999 has 48 divisors (see below), whose sum is σ = 50452480. Its totient is φ = 14696640.

The previous prime is 28089983. The next prime is 28090003. The reversal of 28089999 is 99998082.

It is a Cunningham number, because it is equal to 5300²-1.

It is not a de Polignac number, because 28089999 - 2⁴ = 28089983 is a prime.

It is a Duffinian number.

28089999 is a modest number, since divided by 9999 gives 2808 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28089949) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36729 + ... + 37485.

Almost surely, 2^28089999 is an apocalyptic number.

28089999 is a deficient number, since it is larger than the sum of its proper divisors (22362481).

28089999 is a wasteful number, since it uses less digits than its factorization.

28089999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 54.

The square root of 28089999 is about 5299.9999056604. Note that the first 4 decimals coincide. The cubic root of 28089999 is about 303.9838944318.

The spelling of 28089999 in words is "twenty-eight million, eighty-nine thousand, nine hundred ninety-nine".