28398191 has 4 divisors (see below), whose sum is σ = 28409472. Its totient is φ = 28386912.

The previous prime is 28398173. The next prime is 28398193. The reversal of 28398191 is 19189382.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28398191 - 2²² = 24203887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28398193) 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, 50 + ... + 7536.

It is an arithmetic number, because the mean of its divisors is an integer number (7102368).

Almost surely, 2^28398191 is an apocalyptic number.

28398191 is a deficient number, since it is larger than the sum of its proper divisors (11281).

28398191 is an equidigital number, since it uses as much as digits as its factorization.

28398191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11280.

The product of its digits is 31104, while the sum is 41.

The square root of 28398191 is about 5328.9953086862. The cubic root of 28398191 is about 305.0915822802.

The spelling of 28398191 in words is "twenty-eight million, three hundred ninety-eight thousand, one hundred ninety-one".