28278402 has 8 divisors (see below), whose sum is σ = 56556816. Its totient is φ = 9426132.

The previous prime is 28278401. The next prime is 28278409. The reversal of 28278402 is 20487282.

It is a sphenic number, since it is the product of 3 distinct primes.

28278402 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (28278401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2356528 + ... + 2356539.

It is an arithmetic number, because the mean of its divisors is an integer number (7069602).

Almost surely, 2^28278402 is an apocalyptic number.

28278402 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

28278402 is a wasteful number, since it uses less digits than its factorization.

28278402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4713072.

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

The square root of 28278402 is about 5317.7440705623. The cubic root of 28278402 is about 304.6619994805.

It can be divided in two parts, 28278 and 402, that added together give a triangular number (28680 = T₂₃₉).

The spelling of 28278402 in words is "twenty-eight million, two hundred seventy-eight thousand, four hundred two".