28278420 has 48 divisors (see below), whose sum is σ = 79652160. Its totient is φ = 7495936.

The previous prime is 28278409. The next prime is 28278421. The reversal of 28278420 is 2487282.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28278421) 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, 9424 + ... + 12056.

It is an arithmetic number, because the mean of its divisors is an integer number (1659420).

Almost surely, 2^28278420 is an apocalyptic number.

28278420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28278420 is an abundant number, since it is smaller than the sum of its proper divisors (51373740).

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

28278420 is a wasteful number, since it uses less digits than its factorization.

28278420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824 (or 2822 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 33.

The square root of 28278420 is about 5317.7457630090. The cubic root of 28278420 is about 304.6620641225.

The spelling of 28278420 in words is "twenty-eight million, two hundred seventy-eight thousand, four hundred twenty".