28156938 has 8 divisors (see below), whose sum is σ = 56313888. Its totient is φ = 9385644.

The previous prime is 28156937. The next prime is 28156957. The reversal of 28156938 is 83965182.

It is a sphenic number, since it is the product of 3 distinct primes.

28156938 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 28156938.

It is not an unprimeable number, because it can be changed into a prime (28156937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2346406 + ... + 2346417.

It is an arithmetic number, because the mean of its divisors is an integer number (7039236).

Almost surely, 2^28156938 is an apocalyptic number.

28156938 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

28156938 is a wasteful number, since it uses less digits than its factorization.

28156938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4692828.

The product of its digits is 103680, while the sum is 42.

The square root of 28156938 is about 5306.3111480576. The cubic root of 28156938 is about 304.2251693396.

The spelling of 28156938 in words is "twenty-eight million, one hundred fifty-six thousand, nine hundred thirty-eight".