28278784 has 32 divisors (see below), whose sum is σ = 56622240. Its totient is φ = 14123008.

The previous prime is 28278781. The next prime is 28278791. The reversal of 28278784 is 48787282.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28278781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32337 + ... + 33199.

It is an arithmetic number, because the mean of its divisors is an integer number (1769445).

Almost surely, 2^28278784 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 28278784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28311120).

28278784 is an abundant number, since it is smaller than the sum of its proper divisors (28343456).

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

28278784 is an frugal number, since it uses more digits than its factorization.

28278784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 893 (or 865 counting only the distinct ones).

The product of its digits is 401408, while the sum is 46.

The square root of 28278784 is about 5317.7799879273. The cubic root of 28278784 is about 304.6633713209.

It can be divided in two parts, 2827 and 8784, that added together give a palindrome (11611).

The spelling of 28278784 in words is "twenty-eight million, two hundred seventy-eight thousand, seven hundred eighty-four".