28117878 has 32 divisors (see below), whose sum is σ = 59292000. Its totient is φ = 8875776.

The previous prime is 28117877. The next prime is 28117897. The reversal of 28117878 is 87871182.

Its product of digits (50176) is a multiple of the sum of its prime divisors (3136).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28117871) 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, 7698 + ... + 10746.

It is an arithmetic number, because the mean of its divisors is an integer number (1852875).

Almost surely, 2^28117878 is an apocalyptic number.

28117878 is an abundant number, since it is smaller than the sum of its proper divisors (31174122).

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

28117878 is a wasteful number, since it uses less digits than its factorization.

28117878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3136.

The product of its digits is 50176, while the sum is 42.

The square root of 28117878 is about 5302.6293477859. The cubic root of 28117878 is about 304.0844280160.

The spelling of 28117878 in words is "twenty-eight million, one hundred seventeen thousand, eight hundred seventy-eight".