28243644 has 96 divisors (see below), whose sum is σ = 78650880. Its totient is φ = 7776000.

The previous prime is 28243643. The next prime is 28243661. The reversal of 28243644 is 44634282.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28243643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186969 + ... + 187119.

It is an arithmetic number, because the mean of its divisors is an integer number (819280).

Almost surely, 2^28243644 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 28243644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39325440).

28243644 is an abundant number, since it is smaller than the sum of its proper divisors (50407236).

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

28243644 is a wasteful number, since it uses less digits than its factorization.

28243644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291 (or 289 counting only the distinct ones).

The product of its digits is 36864, while the sum is 33.

The square root of 28243644 is about 5314.4749505478. The cubic root of 28243644 is about 304.5371246336.

The spelling of 28243644 in words is "twenty-eight million, two hundred forty-three thousand, six hundred forty-four".