28217384 has 32 divisors (see below), whose sum is σ = 58525320. Its totient is φ = 12669696.

The previous prime is 28217383. The next prime is 28217401. The reversal of 28217384 is 48371282.

It can be written as a sum of positive squares in 4 ways, for example, as 16176484 + 12040900 = 4022^2 + 3470^2 .

It is not an unprimeable number, because it can be changed into a prime (28217383) 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, 182 + ... + 7514.

Almost surely, 2^28217384 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28217384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29262660).

28217384 is an abundant number, since it is smaller than the sum of its proper divisors (30307936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28217384 is a wasteful number, since it uses less digits than its factorization.

28217384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7389 (or 7385 counting only the distinct ones).

The product of its digits is 21504, while the sum is 35.

The square root of 28217384 is about 5312.0037650589. The cubic root of 28217384 is about 304.4427125402.

The spelling of 28217384 in words is "twenty-eight million, two hundred seventeen thousand, three hundred eighty-four".