28371905 has 4 divisors (see below), whose sum is σ = 34046292. Its totient is φ = 22697520.

The previous prime is 28371901. The next prime is 28371923. The reversal of 28371905 is 50917382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50917382 = 2 ⋅25458691.

It can be written as a sum of positive squares in 2 ways, for example, as 4096576 + 24275329 = 2024^2 + 4927^2 .

It is not a de Polignac number, because 28371905 - 2² = 28371901 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28371901) 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 3 ways as a sum of consecutive naturals, for example, 2837186 + ... + 2837195.

It is an arithmetic number, because the mean of its divisors is an integer number (8511573).

Almost surely, 2^28371905 is an apocalyptic number.

It is an amenable number.

28371905 is a deficient number, since it is larger than the sum of its proper divisors (5674387).

28371905 is an equidigital number, since it uses as much as digits as its factorization.

28371905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5674386.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 28371905 is about 5326.5284191488. The cubic root of 28371905 is about 304.9974200266.

The spelling of 28371905 in words is "twenty-eight million, three hundred seventy-one thousand, nine hundred five".