28189361 has 4 divisors (see below), whose sum is σ = 28200000. Its totient is φ = 28178724.

The previous prime is 28189309. The next prime is 28189393. The reversal of 28189361 is 16398182.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16398182 = 2 ⋅8199091.

It is a cyclic number.

It is not a de Polignac number, because 28189361 - 2¹⁰ = 28188337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28089361) 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, 2180 + ... + 7818.

It is an arithmetic number, because the mean of its divisors is an integer number (7050000).

Almost surely, 2^28189361 is an apocalyptic number.

It is an amenable number.

28189361 is a deficient number, since it is larger than the sum of its proper divisors (10639).

28189361 is an equidigital number, since it uses as much as digits as its factorization.

28189361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10638.

The product of its digits is 20736, while the sum is 38.

The square root of 28189361 is about 5309.3654046411. The cubic root of 28189361 is about 304.3418973370.

The spelling of 28189361 in words is "twenty-eight million, one hundred eighty-nine thousand, three hundred sixty-one".