28806889 has 4 divisors (see below), whose sum is σ = 29800260. Its totient is φ = 27813520.

The previous prime is 28806871. The next prime is 28806919. The reversal of 28806889 is 98860882.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 9517225 = 4392^2 + 3085^2 .

It is a cyclic number.

It is not a de Polignac number, because 28806889 - 2⁷ = 28806761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28806829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496642 + ... + 496699.

It is an arithmetic number, because the mean of its divisors is an integer number (7450065).

Almost surely, 2^28806889 is an apocalyptic number.

28806889 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28806889 is a deficient number, since it is larger than the sum of its proper divisors (993371).

28806889 is an equidigital number, since it uses as much as digits as its factorization.

28806889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 993370.

The product of its (nonzero) digits is 442368, while the sum is 49.

The square root of 28806889 is about 5367.2049523006. The cubic root of 28806889 is about 306.5482113130.

The spelling of 28806889 in words is "twenty-eight million, eight hundred six thousand, eight hundred eighty-nine".