28817213 has 8 divisors (see below), whose sum is σ = 30375000. Its totient is φ = 27297088.

The previous prime is 28817209. The next prime is 28817231. The reversal of 28817213 is 31271882.

It can be written as a sum of positive squares in 4 ways, for example, as 8988004 + 19829209 = 2998^2 + 4453^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 28817213 - 2² = 28817209 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 28817213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28817203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7838 + ... + 10911.

It is an arithmetic number, because the mean of its divisors is an integer number (3796875).

Almost surely, 2^28817213 is an apocalyptic number.

It is an amenable number.

28817213 is a deficient number, since it is larger than the sum of its proper divisors (1557787).

28817213 is a wasteful number, since it uses less digits than its factorization.

28817213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18831.

The product of its digits is 5376, while the sum is 32.

The square root of 28817213 is about 5368.1666330322. The cubic root of 28817213 is about 306.5848278522.

The spelling of 28817213 in words is "twenty-eight million, eight hundred seventeen thousand, two hundred thirteen".