28911845 has 4 divisors (see below), whose sum is σ = 34694220. Its totient is φ = 23129472.

The previous prime is 28911833. The next prime is 28911877. The reversal of 28911845 is 54811982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54811982 = 2 ⋅27405991.

It can be written as a sum of positive squares in 2 ways, for example, as 12517444 + 16394401 = 3538^2 + 4049^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28911845 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28911799 and 28911808.

It is a congruent number.

It is an unprimeable number.

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, 2891180 + ... + 2891189.

It is an arithmetic number, because the mean of its divisors is an integer number (8673555).

Almost surely, 2^28911845 is an apocalyptic number.

It is an amenable number.

28911845 is a deficient number, since it is larger than the sum of its proper divisors (5782375).

28911845 is an equidigital number, since it uses as much as digits as its factorization.

28911845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5782374.

The product of its digits is 23040, while the sum is 38.

The square root of 28911845 is about 5376.9735911570. The cubic root of 28911845 is about 306.9200561434.

The spelling of 28911845 in words is "twenty-eight million, nine hundred eleven thousand, eight hundred forty-five".