28245121 has 4 divisors (see below), whose sum is σ = 28271700. Its totient is φ = 28218544.

The previous prime is 28245079. The next prime is 28245157. The reversal of 28245121 is 12154282.

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 9235521 + 19009600 = 3039^2 + 4360^2 .

It is a cyclic number.

It is not a de Polignac number, because 28245121 - 2⁹ = 28244609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28245521) 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, 11626 + ... + 13843.

It is an arithmetic number, because the mean of its divisors is an integer number (7067925).

Almost surely, 2^28245121 is an apocalyptic number.

It is an amenable number.

28245121 is a deficient number, since it is larger than the sum of its proper divisors (26579).

28245121 is a wasteful number, since it uses less digits than its factorization.

28245121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26578.

The product of its digits is 1280, while the sum is 25.

The square root of 28245121 is about 5314.6139088367. The cubic root of 28245121 is about 304.5424331258.

The spelling of 28245121 in words is "twenty-eight million, two hundred forty-five thousand, one hundred twenty-one".