28140217 has 4 divisors (see below), whose sum is σ = 32160256. Its totient is φ = 24120180.

The previous prime is 28140199. The next prime is 28140269. The reversal of 28140217 is 71204182.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28140217 - 2⁷ = 28140089 is a prime.

It is a super-3 number, since 3×28140217³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28140191 and 28140200.

It is not an unprimeable number, because it can be changed into a prime (28140517) 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, 2010009 + ... + 2010022.

It is an arithmetic number, because the mean of its divisors is an integer number (8040064).

Almost surely, 2^28140217 is an apocalyptic number.

It is an amenable number.

28140217 is a deficient number, since it is larger than the sum of its proper divisors (4020039).

28140217 is an equidigital number, since it uses as much as digits as its factorization.

28140217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4020038.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 28140217 is about 5304.7353374132. The cubic root of 28140217 is about 304.1649360340.

Adding to 28140217 its reverse (71204182), we get a palindrome (99344399).

The spelling of 28140217 in words is "twenty-eight million, one hundred forty thousand, two hundred seventeen".