28108121 has 4 divisors (see below), whose sum is σ = 28464000. Its totient is φ = 27752244.

The previous prime is 28108109. The next prime is 28108177. The reversal of 28108121 is 12180182.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28108121 - 2¹⁰ = 28107097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28108321) 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, 177821 + ... + 177978.

It is an arithmetic number, because the mean of its divisors is an integer number (7116000).

Almost surely, 2^28108121 is an apocalyptic number.

It is an amenable number.

28108121 is a deficient number, since it is larger than the sum of its proper divisors (355879).

28108121 is an equidigital number, since it uses as much as digits as its factorization.

28108121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355878.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 28108121 is about 5301.7092526845. The cubic root of 28108121 is about 304.0492511674.

The spelling of 28108121 in words is "twenty-eight million, one hundred eight thousand, one hundred twenty-one".