28321271 has 4 divisors (see below), whose sum is σ = 30895944. Its totient is φ = 25746600.

The previous prime is 28321253. The next prime is 28321301. The reversal of 28321271 is 17212382.

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

It is not a de Polignac number, because 28321271 - 2¹⁰ = 28320247 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 28321271.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28321171) 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, 1287320 + ... + 1287341.

It is an arithmetic number, because the mean of its divisors is an integer number (7723986).

Almost surely, 2^28321271 is an apocalyptic number.

28321271 is a deficient number, since it is larger than the sum of its proper divisors (2574673).

28321271 is a wasteful number, since it uses less digits than its factorization.

28321271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2574672.

The product of its digits is 1344, while the sum is 26.

The square root of 28321271 is about 5321.7732946829. The cubic root of 28321271 is about 304.8158738171.

Subtracting from 28321271 its reverse (17212382), we obtain a square (11108889 = 3333²).

The spelling of 28321271 in words is "twenty-eight million, three hundred twenty-one thousand, two hundred seventy-one".