28663989 has 16 divisors (see below), whose sum is σ = 42598080. Its totient is φ = 17038080.

The previous prime is 28663939. The next prime is 28664071. The reversal of 28663989 is 98936682.

It is not a de Polignac number, because 28663989 - 2¹⁵ = 28631221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28663939) 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 15 ways as a sum of consecutive naturals, for example, 13822 + ... + 15759.

It is an arithmetic number, because the mean of its divisors is an integer number (2662380).

Almost surely, 2^28663989 is an apocalyptic number.

It is an amenable number.

28663989 is a deficient number, since it is larger than the sum of its proper divisors (13934091).

28663989 is a wasteful number, since it uses less digits than its factorization.

28663989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29620.

The product of its digits is 1119744, while the sum is 51.

The square root of 28663989 is about 5353.8760725291. The cubic root of 28663989 is about 306.0404812094.

The spelling of 28663989 in words is "twenty-eight million, six hundred sixty-three thousand, nine hundred eighty-nine".