28731878 has 16 divisors (see below), whose sum is σ = 49991424. Its totient is φ = 12129480.

The previous prime is 28731877. The next prime is 28731881. The reversal of 28731878 is 87813782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28731877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14378 + ... + 16253.

It is an arithmetic number, because the mean of its divisors is an integer number (3124464).

Almost surely, 2^28731878 is an apocalyptic number.

28731878 is a deficient number, since it is larger than the sum of its proper divisors (21259546).

28731878 is a wasteful number, since it uses less digits than its factorization.

28731878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30707.

The product of its digits is 150528, while the sum is 44.

The square root of 28731878 is about 5360.2124957878. The cubic root of 28731878 is about 306.2819037706.

The spelling of 28731878 in words is "twenty-eight million, seven hundred thirty-one thousand, eight hundred seventy-eight".