28319447 has 4 divisors (see below), whose sum is σ = 30497880. Its totient is φ = 26141016.

The previous prime is 28319429. The next prime is 28319453. The reversal of 28319447 is 74491382.

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 28319447 - 2⁸ = 28319191 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28319447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28319497) 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, 1089197 + ... + 1089222.

It is an arithmetic number, because the mean of its divisors is an integer number (7624470).

Almost surely, 2^28319447 is an apocalyptic number.

28319447 is a deficient number, since it is larger than the sum of its proper divisors (2178433).

28319447 is a wasteful number, since it uses less digits than its factorization.

28319447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2178432.

The product of its digits is 48384, while the sum is 38.

The square root of 28319447 is about 5321.6019204747. The cubic root of 28319447 is about 304.8093299007.

The spelling of 28319447 in words is "twenty-eight million, three hundred nineteen thousand, four hundred forty-seven".