28917229 has 4 divisors (see below), whose sum is σ = 31546080. Its totient is φ = 26288380.

The previous prime is 28917211. The next prime is 28917241. The reversal of 28917229 is 92271982.

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 a cyclic number.

It is not a de Polignac number, because 28917229 - 2⁵ = 28917197 is a prime.

It is a super-2 number, since 2×28917229² = 1672412266076882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28917191 and 28917200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28917269) 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 3 ways as a sum of consecutive naturals, for example, 1314409 + ... + 1314430.

It is an arithmetic number, because the mean of its divisors is an integer number (7886520).

Almost surely, 2^28917229 is an apocalyptic number.

It is an amenable number.

28917229 is a deficient number, since it is larger than the sum of its proper divisors (2628851).

28917229 is a wasteful number, since it uses less digits than its factorization.

28917229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628850.

The product of its digits is 36288, while the sum is 40.

The square root of 28917229 is about 5377.4742212306. The cubic root of 28917229 is about 306.9391066401.

The spelling of 28917229 in words is "twenty-eight million, nine hundred seventeen thousand, two hundred twenty-nine".