28218889 has 2 divisors, whose sum is σ = 28218890. Its totient is φ = 28218888.

The previous prime is 28218881. The next prime is 28218893. The reversal of 28218889 is 98881282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24950025 + 3268864 = 4995^2 + 1808^2 .

It is a cyclic number.

It is not a de Polignac number, because 28218889 - 2³ = 28218881 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28218881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14109444 + 14109445.

It is an arithmetic number, because the mean of its divisors is an integer number (14109445).

Almost surely, 2^28218889 is an apocalyptic number.

It is an amenable number.

28218889 is a deficient number, since it is larger than the sum of its proper divisors (1).

28218889 is an equidigital number, since it uses as much as digits as its factorization.

28218889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 147456, while the sum is 46.

The square root of 28218889 is about 5312.1454234612. The cubic root of 28218889 is about 304.4481250209.

The spelling of 28218889 in words is "twenty-eight million, two hundred eighteen thousand, eight hundred eighty-nine".