28178013 has 16 divisors (see below), whose sum is σ = 39384576. Its totient is φ = 17886000.

The previous prime is 28178011. The next prime is 28178021. The reversal of 28178013 is 31087182.

It is a happy number.

It is not a de Polignac number, because 28178013 - 2¹ = 28178011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28178011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16506 + ... + 18132.

It is an arithmetic number, because the mean of its divisors is an integer number (2461536).

Almost surely, 2^28178013 is an apocalyptic number.

28178013 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

28178013 is a deficient number, since it is larger than the sum of its proper divisors (11206563).

28178013 is a wasteful number, since it uses less digits than its factorization.

28178013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1904.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 28178013 is about 5308.2966194439. The cubic root of 28178013 is about 304.3010529041.

The spelling of 28178013 in words is "twenty-eight million, one hundred seventy-eight thousand, thirteen".