28255121 has 4 divisors (see below), whose sum is σ = 28318500. Its totient is φ = 28191744.

The previous prime is 28255111. The next prime is 28255127. The reversal of 28255121 is 12155282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12155282 = 2 ⋅6077641.

It can be written as a sum of positive squares in 2 ways, for example, as 18395521 + 9859600 = 4289^2 + 3140^2 .

It is a cyclic number.

It is not a de Polignac number, because 28255121 - 2⁶ = 28255057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28255127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31016 + ... + 31913.

It is an arithmetic number, because the mean of its divisors is an integer number (7079625).

Almost surely, 2^28255121 is an apocalyptic number.

It is an amenable number.

28255121 is a deficient number, since it is larger than the sum of its proper divisors (63379).

28255121 is an equidigital number, since it uses as much as digits as its factorization.

28255121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63378.

The product of its digits is 1600, while the sum is 26.

The square root of 28255121 is about 5315.5546276941. The cubic root of 28255121 is about 304.5783693028.

The spelling of 28255121 in words is "twenty-eight million, two hundred fifty-five thousand, one hundred twenty-one".