28004201 has 4 divisors (see below), whose sum is σ = 28024452. Its totient is φ = 27983952.

The previous prime is 28004161. The next prime is 28004209. The reversal of 28004201 is 10240082.

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 20976400 + 7027801 = 4580^2 + 2651^2 .

It is a cyclic number.

It is not a de Polignac number, because 28004201 - 2¹⁰ = 28003177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28004201.

It is not an unprimeable number, because it can be changed into a prime (28004209) 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, 7886 + ... + 10871.

It is an arithmetic number, because the mean of its divisors is an integer number (7006113).

Almost surely, 2^28004201 is an apocalyptic number.

It is an amenable number.

28004201 is a deficient number, since it is larger than the sum of its proper divisors (20251).

28004201 is a wasteful number, since it uses less digits than its factorization.

28004201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20250.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 28004201 is about 5291.8995644286. The cubic root of 28004201 is about 303.6740829880.

Adding to 28004201 its reverse (10240082), we get a palindrome (38244283).

The spelling of 28004201 in words is "twenty-eight million, four thousand, two hundred one".