28888889 has 2 divisors, whose sum is σ = 28888890. Its totient is φ = 28888888.

The previous prime is 28888883. The next prime is 28888891. The reversal of 28888889 is 98888882.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28174864 + 714025 = 5308^2 + 845^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28888889 is a prime.

It is a Sophie Germain prime.

Together with 28888891, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (28888883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14444444 + 14444445.

It is an arithmetic number, because the mean of its divisors is an integer number (14444445).

Almost surely, 2^28888889 is an apocalyptic number.

It is an amenable number.

28888889 is a deficient number, since it is larger than the sum of its proper divisors (1).

28888889 is an equidigital number, since it uses as much as digits as its factorization.

28888889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4718592, while the sum is 59.

The square root of 28888889 is about 5374.8385092019. The cubic root of 28888889 is about 306.8388031439.

The spelling of 28888889 in words is "twenty-eight million, eight hundred eighty-eight thousand, eight hundred eighty-nine".