28138544 has 60 divisors (see below), whose sum is σ = 66792600. Its totient is φ = 11418624.

The previous prime is 28138543. The next prime is 28138547. The reversal of 28138544 is 44583182.

It is not an unprimeable number, because it can be changed into a prime (28138543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13952 + ... + 15840.

It is an arithmetic number, because the mean of its divisors is an integer number (1113210).

Almost surely, 2^28138544 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 28138544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33396300).

28138544 is an abundant number, since it is smaller than the sum of its proper divisors (38654056).

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

28138544 is a wasteful number, since it uses less digits than its factorization.

28138544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1930 (or 1917 counting only the distinct ones).

The product of its digits is 30720, while the sum is 35.

The square root of 28138544 is about 5304.5776457697. The cubic root of 28138544 is about 304.1589081485.

It can be divided in two parts, 28138 and 544, that added together give a palindrome (28682).

The spelling of 28138544 in words is "twenty-eight million, one hundred thirty-eight thousand, five hundred forty-four".