28138446 has 72 divisors (see below), whose sum is σ = 72220824. Its totient is φ = 7892640.

The previous prime is 28138433. The next prime is 28138471. The reversal of 28138446 is 64483182.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28138446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 53541 + ... + 54063.

It is an arithmetic number, because the mean of its divisors is an integer number (1003067).

Almost surely, 2^28138446 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28138446, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36110412).

28138446 is an abundant number, since it is smaller than the sum of its proper divisors (44082378).

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

28138446 is a wasteful number, since it uses less digits than its factorization.

28138446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606 (or 596 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 28138446 is about 5304.5684084570. The cubic root of 28138446 is about 304.1585550432.

The spelling of 28138446 in words is "twenty-eight million, one hundred thirty-eight thousand, four hundred forty-six".