28178840 has 32 divisors (see below), whose sum is σ = 63558000. Its totient is φ = 11243904.

The previous prime is 28178833. The next prime is 28178861. The reversal of 28178840 is 4887182.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 28178794 and 28178803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25826 + ... + 26894.

Almost surely, 2^28178840 is an apocalyptic number.

28178840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28178840 is an abundant number, since it is smaller than the sum of its proper divisors (35379160).

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

28178840 is a wasteful number, since it uses less digits than its factorization.

28178840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1739 (or 1735 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 28178840 is about 5308.3745158005. The cubic root of 28178840 is about 304.3040298648.

The spelling of 28178840 in words is "twenty-eight million, one hundred seventy-eight thousand, eight hundred forty".