28138518 has 24 divisors (see below), whose sum is σ = 61117056. Its totient is φ = 9356400.

The previous prime is 28138511. The next prime is 28138529. The reversal of 28138518 is 81583182.

28138518 is a `hidden beast` number, since 2 + 8 + 138 + 518 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28138511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6603 + ... + 9993.

It is an arithmetic number, because the mean of its divisors is an integer number (2546544).

Almost surely, 2^28138518 is an apocalyptic number.

28138518 is an abundant number, since it is smaller than the sum of its proper divisors (32978538).

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

28138518 is a wasteful number, since it uses less digits than its factorization.

28138518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3860 (or 3857 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 28138518 is about 5304.5751950557. The cubic root of 28138518 is about 304.1588144675.

The spelling of 28138518 in words is "twenty-eight million, one hundred thirty-eight thousand, five hundred eighteen".