28816989 has 8 divisors (see below), whose sum is σ = 40682880. Its totient is φ = 18081216.

The previous prime is 28816979. The next prime is 28816993. The reversal of 28816989 is 98961882.

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

It is not a de Polignac number, because 28816989 - 2⁹ = 28816477 is a prime.

It is a super-2 number, since 2×28816989² = 1660837710052242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 565039 = 28816989 / (2 + 8 + 8 + 1 + 6 + 9 + 8 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28816979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 282469 + ... + 282570.

It is an arithmetic number, because the mean of its divisors is an integer number (5085360).

Almost surely, 2^28816989 is an apocalyptic number.

It is an amenable number.

28816989 is a deficient number, since it is larger than the sum of its proper divisors (11865891).

28816989 is a wasteful number, since it uses less digits than its factorization.

28816989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565059.

The product of its digits is 497664, while the sum is 51.

The square root of 28816989 is about 5368.1457692578. The cubic root of 28816989 is about 306.5840334753.

It can be divided in two parts, 2881 and 6989, that added together give a triangular number (9870 = T₁₄₀).

The spelling of 28816989 in words is "twenty-eight million, eight hundred sixteen thousand, nine hundred eighty-nine".