28107389 has 4 divisors (see below), whose sum is σ = 28118556. Its totient is φ = 28096224.

The previous prime is 28107379. The next prime is 28107407. The reversal of 28107389 is 98370182.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2199289 + 25908100 = 1483^2 + 5090^2 .

It is a cyclic number.

It is not a de Polignac number, because 28107389 - 2⁸ = 28107133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28107349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167 + ... + 7499.

It is an arithmetic number, because the mean of its divisors is an integer number (7029639).

Almost surely, 2^28107389 is an apocalyptic number.

It is an amenable number.

28107389 is a deficient number, since it is larger than the sum of its proper divisors (11167).

28107389 is an equidigital number, since it uses as much as digits as its factorization.

28107389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11166.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 28107389 is about 5301.6402178948. The cubic root of 28107389 is about 304.0466117643.

The spelling of 28107389 in words is "twenty-eight million, one hundred seven thousand, three hundred eighty-nine".