28169978 has 16 divisors (see below), whose sum is σ = 43148160. Its totient is φ = 13790400.

The previous prime is 28169971. The next prime is 28170007. The reversal of 28169978 is 87996182.

It is not an unprimeable number, because it can be changed into a prime (28169971) 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 7 ways as a sum of consecutive naturals, for example, 20018 + ... + 21378.

It is an arithmetic number, because the mean of its divisors is an integer number (2696760).

Almost surely, 2^28169978 is an apocalyptic number.

28169978 is a deficient number, since it is larger than the sum of its proper divisors (14978182).

28169978 is a wasteful number, since it uses less digits than its factorization.

28169978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573.

The product of its digits is 435456, while the sum is 50.

The square root of 28169978 is about 5307.5397313633. The cubic root of 28169978 is about 304.2721261968.

The spelling of 28169978 in words is "twenty-eight million, one hundred sixty-nine thousand, nine hundred seventy-eight".