28221171 has 8 divisors (see below), whose sum is σ = 41049024. Its totient is φ = 17103720.

The previous prime is 28221169. The next prime is 28221181. The reversal of 28221171 is 17112282.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28221171 - 2¹ = 28221169 is a prime.

It is a super-2 number, since 2×28221171² = 1592868985222482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28221181) 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 7 ways as a sum of consecutive naturals, for example, 427561 + ... + 427626.

It is an arithmetic number, because the mean of its divisors is an integer number (5131128).

Almost surely, 2^28221171 is an apocalyptic number.

28221171 is a deficient number, since it is larger than the sum of its proper divisors (12827853).

28221171 is a wasteful number, since it uses less digits than its factorization.

28221171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855201.

The product of its digits is 448, while the sum is 24.

The square root of 28221171 is about 5312.3602099255. The cubic root of 28221171 is about 304.4563314849.

Subtracting from 28221171 its reverse (17112282), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 282211 and 71, that added together give a palindrome (282282).

The spelling of 28221171 in words is "twenty-eight million, two hundred twenty-one thousand, one hundred seventy-one".