28811217 has 8 divisors (see below), whose sum is σ = 38447296. Its totient is φ = 19191312.

The previous prime is 28811213. The next prime is 28811219. The reversal of 28811217 is 71211882.

It is a happy number.

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

It is not a de Polignac number, because 28811217 - 2² = 28811213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28811213) 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, 1023 + ... + 7659.

It is an arithmetic number, because the mean of its divisors is an integer number (4805912).

Almost surely, 2^28811217 is an apocalyptic number.

It is an amenable number.

28811217 is a deficient number, since it is larger than the sum of its proper divisors (9636079).

28811217 is a wasteful number, since it uses less digits than its factorization.

28811217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8087.

The product of its digits is 1792, while the sum is 30.

The square root of 28811217 is about 5367.6081265308. The cubic root of 28811217 is about 306.5635626667.

The spelling of 28811217 in words is "twenty-eight million, eight hundred eleven thousand, two hundred seventeen".