28048421 has 4 divisors (see below), whose sum is σ = 28253292. Its totient is φ = 27843552.

The previous prime is 28048417. The next prime is 28048429. The reversal of 28048421 is 12484082.

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 7924225 + 20124196 = 2815^2 + 4486^2 .

It is a cyclic number.

It is not a de Polignac number, because 28048421 - 2² = 28048417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28048429) 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, 102230 + ... + 102503.

It is an arithmetic number, because the mean of its divisors is an integer number (7063323).

Almost surely, 2^28048421 is an apocalyptic number.

It is an amenable number.

28048421 is a deficient number, since it is larger than the sum of its proper divisors (204871).

28048421 is a wasteful number, since it uses less digits than its factorization.

28048421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204870.

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 28048421 is about 5296.0760002100. The cubic root of 28048421 is about 303.8338376628.

The spelling of 28048421 in words is "twenty-eight million, forty-eight thousand, four hundred twenty-one".