28378278 has 12 divisors (see below), whose sum is σ = 61486308. Its totient is φ = 9459420.

The previous prime is 28378261. The next prime is 28378279. The reversal of 28378278 is 87287382.

28378278 is a `hidden beast` number, since 2 + 8 + 378 + 278 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28378279) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 788268 + ... + 788303.

It is an arithmetic number, because the mean of its divisors is an integer number (5123859).

Almost surely, 2^28378278 is an apocalyptic number.

28378278 is an abundant number, since it is smaller than the sum of its proper divisors (33108030).

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

28378278 is a wasteful number, since it uses less digits than its factorization.

28378278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1576579 (or 1576576 counting only the distinct ones).

The product of its digits is 301056, while the sum is 45.

The square root of 28378278 is about 5327.1266176054. The cubic root of 28378278 is about 305.0202548584.

The spelling of 28378278 in words is "twenty-eight million, three hundred seventy-eight thousand, two hundred seventy-eight".