28220416 has 88 divisors (see below), whose sum is σ = 67076096. Its totient is φ = 11612160.

The previous prime is 28220411. The next prime is 28220417. The reversal of 28220416 is 61402282.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28220411) 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, 222145 + ... + 222271.

Almost surely, 2^28220416 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 28220416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33538048).

28220416 is an abundant number, since it is smaller than the sum of its proper divisors (38855680).

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

28220416 is a wasteful number, since it uses less digits than its factorization.

28220416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 28220416 is about 5312.2891487569. The cubic root of 28220416 is about 304.4536164242.

Adding to 28220416 its reverse (61402282), we get a palindrome (89622698).

The spelling of 28220416 in words is "twenty-eight million, two hundred twenty thousand, four hundred sixteen".