28259689 has 4 divisors (see below), whose sum is σ = 28551124. Its totient is φ = 27968256.

The previous prime is 28259681. The next prime is 28259719. The reversal of 28259689 is 98695282.

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 8970025 + 19289664 = 2995^2 + 4392^2 .

It is a cyclic number.

It is not a de Polignac number, because 28259689 - 2³ = 28259681 is a prime.

It is a super-2 number, since 2×28259689² = 1597220044753442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28259681) 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, 145572 + ... + 145765.

It is an arithmetic number, because the mean of its divisors is an integer number (7137781).

Almost surely, 2^28259689 is an apocalyptic number.

It is an amenable number.

28259689 is a deficient number, since it is larger than the sum of its proper divisors (291435).

28259689 is an equidigital number, since it uses as much as digits as its factorization.

28259689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291434.

The product of its digits is 622080, while the sum is 49.

The square root of 28259689 is about 5315.9842926781. The cubic root of 28259689 is about 304.5947821272.

The spelling of 28259689 in words is "twenty-eight million, two hundred fifty-nine thousand, six hundred eighty-nine".