28906289 has 4 divisors (see below), whose sum is σ = 28919280. Its totient is φ = 28893300.

The previous prime is 28906261. The next prime is 28906303. The reversal of 28906289 is 98260982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98260982 = 2 ⋅49130491.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28906289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28906219) 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, 2219 + ... + 7920.

It is an arithmetic number, because the mean of its divisors is an integer number (7229820).

Almost surely, 2^28906289 is an apocalyptic number.

It is an amenable number.

28906289 is a deficient number, since it is larger than the sum of its proper divisors (12991).

28906289 is a wasteful number, since it uses less digits than its factorization.

28906289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12990.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 28906289 is about 5376.4569188267. The cubic root of 28906289 is about 306.9003945701.

The spelling of 28906289 in words is "twenty-eight million, nine hundred six thousand, two hundred eighty-nine".