28278630 has 48 divisors (see below), whose sum is σ = 73906560. Its totient is φ = 7501824.

The previous prime is 28278617. The next prime is 28278671. The reversal of 28278630 is 3687282.

It is a happy number.

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, 19366 + ... + 20774.

It is an arithmetic number, because the mean of its divisors is an integer number (1539720).

Almost surely, 2^28278630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28278630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36953280).

28278630 is an abundant number, since it is smaller than the sum of its proper divisors (45627930).

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

28278630 is a wasteful number, since it uses less digits than its factorization.

28278630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645 (or 1642 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 28278630 is about 5317.7655081810. The cubic root of 28278630 is about 304.6628182768.

The spelling of 28278630 in words is "twenty-eight million, two hundred seventy-eight thousand, six hundred thirty".