28120211 has 4 divisors (see below), whose sum is σ = 32137392. Its totient is φ = 24103032.

The previous prime is 28120201. The next prime is 28120217. The reversal of 28120211 is 11202182.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28120211 - 2¹⁴ = 28103827 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28120211.

It is not an unprimeable number, because it can be changed into a prime (28120217) 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, 2008580 + ... + 2008593.

It is an arithmetic number, because the mean of its divisors is an integer number (8034348).

Almost surely, 2^28120211 is an apocalyptic number.

28120211 is a deficient number, since it is larger than the sum of its proper divisors (4017181).

28120211 is an equidigital number, since it uses as much as digits as its factorization.

28120211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017180.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 28120211 is about 5302.8493284271. The cubic root of 28120211 is about 304.0928379601.

Adding to 28120211 its reverse (11202182), we get a palindrome (39322393).

The spelling of 28120211 in words is "twenty-eight million, one hundred twenty thousand, two hundred eleven".