28349521 has 4 divisors (see below), whose sum is σ = 28393200. Its totient is φ = 28305844.

The previous prime is 28349479. The next prime is 28349549. The reversal of 28349521 is 12594382.

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 28349521 - 2⁷ = 28349393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28349561) 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, 20851 + ... + 22168.

It is an arithmetic number, because the mean of its divisors is an integer number (7098300).

Almost surely, 2^28349521 is an apocalyptic number.

It is an amenable number.

28349521 is a deficient number, since it is larger than the sum of its proper divisors (43679).

28349521 is an equidigital number, since it uses as much as digits as its factorization.

28349521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43678.

The product of its digits is 17280, while the sum is 34.

The square root of 28349521 is about 5324.4268236121. The cubic root of 28349521 is about 304.9171897372.

The spelling of 28349521 in words is "twenty-eight million, three hundred forty-nine thousand, five hundred twenty-one".