28107521 has 8 divisors (see below), whose sum is σ = 30416064. Its totient is φ = 25819920.

The previous prime is 28107487. The next prime is 28107529. The reversal of 28107521 is 12570182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28107521 - 2¹⁴ = 28091137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28107529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2381 + ... + 7866.

It is an arithmetic number, because the mean of its divisors is an integer number (3802008).

Almost surely, 2^28107521 is an apocalyptic number.

It is an amenable number.

28107521 is a deficient number, since it is larger than the sum of its proper divisors (2308543).

28107521 is a wasteful number, since it uses less digits than its factorization.

28107521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10471.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 28107521 is about 5301.6526668578. The cubic root of 28107521 is about 304.0470877256.

The spelling of 28107521 in words is "twenty-eight million, one hundred seven thousand, five hundred twenty-one".