28719291 has 4 divisors (see below), whose sum is σ = 38292392. Its totient is φ = 19146192.

The previous prime is 28719281. The next prime is 28719293. The reversal of 28719291 is 19291782.

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

It is not a de Polignac number, because 28719291 - 2⁹ = 28718779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28719293) 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, 4786546 + ... + 4786551.

It is an arithmetic number, because the mean of its divisors is an integer number (9573098).

Almost surely, 2^28719291 is an apocalyptic number.

28719291 is a deficient number, since it is larger than the sum of its proper divisors (9573101).

28719291 is an equidigital number, since it uses as much as digits as its factorization.

28719291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9573100.

The product of its digits is 18144, while the sum is 39.

The square root of 28719291 is about 5359.0382532690. The cubic root of 28719291 is about 306.2371714188.

The spelling of 28719291 in words is "twenty-eight million, seven hundred nineteen thousand, two hundred ninety-one".