28109386 has 16 divisors (see below), whose sum is σ = 42789384. Its totient is φ = 13848064.

The previous prime is 28109383. The next prime is 28109387. The reversal of 28109386 is 68390182.

It can be written as a sum of positive squares in 4 ways, for example, as 28037025 + 72361 = 5295^2 + 269^2 .

It is not an unprimeable number, because it can be changed into a prime (28109383) 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 7 ways as a sum of consecutive naturals, for example, 47106 + ... + 47698.

Almost surely, 2^28109386 is an apocalyptic number.

28109386 is a deficient number, since it is larger than the sum of its proper divisors (14679998).

28109386 is a wasteful number, since it uses less digits than its factorization.

28109386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 28109386 is about 5301.8285524902. The cubic root of 28109386 is about 304.0538123229.

The spelling of 28109386 in words is "twenty-eight million, one hundred nine thousand, three hundred eighty-six".