28313491 has 4 divisors (see below), whose sum is σ = 28377000. Its totient is φ = 28249984.

The previous prime is 28313443. The next prime is 28313503. The reversal of 28313491 is 19431382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28313491 - 2¹⁵ = 28280723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28313191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31081 + ... + 31978.

It is an arithmetic number, because the mean of its divisors is an integer number (7094250).

Almost surely, 2^28313491 is an apocalyptic number.

28313491 is a deficient number, since it is larger than the sum of its proper divisors (63509).

28313491 is an equidigital number, since it uses as much as digits as its factorization.

28313491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63508.

The product of its digits is 5184, while the sum is 31.

The square root of 28313491 is about 5321.0422851167. The cubic root of 28313491 is about 304.7879597605.

The spelling of 28313491 in words is "twenty-eight million, three hundred thirteen thousand, four hundred ninety-one".