28013845 has 4 divisors (see below), whose sum is σ = 33616620. Its totient is φ = 22411072.

The previous prime is 28013819. The next prime is 28013851. The reversal of 28013845 is 54831082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18335524 + 9678321 = 4282^2 + 3111^2 .

It is a cyclic number.

It is not a de Polignac number, because 28013845 - 2¹⁵ = 27981077 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2801380 + ... + 2801389.

It is an arithmetic number, because the mean of its divisors is an integer number (8404155).

Almost surely, 2^28013845 is an apocalyptic number.

It is an amenable number.

28013845 is a deficient number, since it is larger than the sum of its proper divisors (5602775).

28013845 is an equidigital number, since it uses as much as digits as its factorization.

28013845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5602774.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 28013845 is about 5292.8106899832. The cubic root of 28013845 is about 303.7089384338.

The spelling of 28013845 in words is "twenty-eight million, thirteen thousand, eight hundred forty-five".