28138760 has 64 divisors (see below), whose sum is σ = 69536880. Its totient is φ = 10183680.

The previous prime is 28138741. The next prime is 28138763. The reversal of 28138760 is 6783182.

It can be written as a sum of positive squares in 8 ways, for example, as 10982596 + 17156164 = 3314^2 + 4142^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28138760.

It is not an unprimeable number, because it can be changed into a prime (28138763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27050 + ... + 28070.

Almost surely, 2^28138760 is an apocalyptic number.

28138760 is a gapful number since it is divisible by the number (20) 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 28138760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34768440).

28138760 is an abundant number, since it is smaller than the sum of its proper divisors (41398120).

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

28138760 is a wasteful number, since it uses less digits than its factorization.

28138760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098 (or 1094 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 28138760 is about 5304.5980055043. The cubic root of 28138760 is about 304.1596864185.

The spelling of 28138760 in words is "twenty-eight million, one hundred thirty-eight thousand, seven hundred sixty".