28218384 has 60 divisors (see below), whose sum is σ = 79645696. Its totient is φ = 9326016.

The previous prime is 28218371. The next prime is 28218391. The reversal of 28218384 is 48381282.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17517 + ... + 19059.

Almost surely, 2^28218384 is an apocalyptic number.

28218384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28218384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39822848).

28218384 is an abundant number, since it is smaller than the sum of its proper divisors (51427312).

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

28218384 is a wasteful number, since it uses less digits than its factorization.

28218384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1684 (or 1675 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 28218384 is about 5312.0978906643. The cubic root of 28218384 is about 304.4463088943.

The spelling of 28218384 in words is "twenty-eight million, two hundred eighteen thousand, three hundred eighty-four".