28278396 has 72 divisors (see below), whose sum is σ = 75828480. Its totient is φ = 9210672.

The previous prime is 28278373. The next prime is 28278401. The reversal of 28278396 is 69387282.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45375 + ... + 45993.

Almost surely, 2^28278396 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 28278396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37914240).

28278396 is an abundant number, since it is smaller than the sum of its proper divisors (47550084).

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

28278396 is a wasteful number, since it uses less digits than its factorization.

28278396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685 (or 671 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 28278396 is about 5317.7435064132. The cubic root of 28278396 is about 304.6619779332.

The spelling of 28278396 in words is "twenty-eight million, two hundred seventy-eight thousand, three hundred ninety-six".