28269391 has 4 divisors (see below), whose sum is σ = 28330912. Its totient is φ = 28207872.

The previous prime is 28269379. The next prime is 28269401. The reversal of 28269391 is 19396282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19396282 = 2 ⋅9698141.

It is a cyclic number.

It is not a de Polignac number, because 28269391 - 2⁹ = 28268879 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 (28269091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30066 + ... + 30991.

It is an arithmetic number, because the mean of its divisors is an integer number (7082728).

Almost surely, 2^28269391 is an apocalyptic number.

28269391 is a deficient number, since it is larger than the sum of its proper divisors (61521).

28269391 is an equidigital number, since it uses as much as digits as its factorization.

28269391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61520.

The product of its digits is 46656, while the sum is 40.

The square root of 28269391 is about 5316.8967452829. The cubic root of 28269391 is about 304.6296355475.

The spelling of 28269391 in words is "twenty-eight million, two hundred sixty-nine thousand, three hundred ninety-one".