28147805 has 12 divisors (see below), whose sum is σ = 39292380. Its totient is φ = 19301184.

The previous prime is 28147793. The next prime is 28147807. The reversal of 28147805 is 50874182.

It can be written as a sum of positive squares in 2 ways, for example, as 12945604 + 15202201 = 3598^2 + 3899^2 .

It is not a de Polignac number, because 28147805 - 2²⁰ = 27099229 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28147807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57200 + ... + 57689.

It is an arithmetic number, because the mean of its divisors is an integer number (3274365).

Almost surely, 2^28147805 is an apocalyptic number.

It is an amenable number.

28147805 is a deficient number, since it is larger than the sum of its proper divisors (11144575).

28147805 is a wasteful number, since it uses less digits than its factorization.

28147805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114908 (or 114901 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 28147805 is about 5305.4504992507. The cubic root of 28147805 is about 304.1922729011.

The spelling of 28147805 in words is "twenty-eight million, one hundred forty-seven thousand, eight hundred five".