28223712 has 144 divisors (see below), whose sum is σ = 89631360. Its totient is φ = 8352000.

The previous prime is 28223687. The next prime is 28223717. The reversal of 28223712 is 21732282.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28223717) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 186837 + ... + 186987.

It is an arithmetic number, because the mean of its divisors is an integer number (622440).

Almost surely, 2^28223712 is an apocalyptic number.

28223712 is a gapful number since it is divisible by the number (22) 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 28223712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44815680).

28223712 is an abundant number, since it is smaller than the sum of its proper divisors (61407648).

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

28223712 is a wasteful number, since it uses less digits than its factorization.

28223712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 226 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 28223712 is about 5312.5993637766. The cubic root of 28223712 is about 304.4654688369.

Adding to 28223712 its reverse (21732282), we get a palindrome (49955994).

The spelling of 28223712 in words is "twenty-eight million, two hundred twenty-three thousand, seven hundred twelve".