28065521 has 8 divisors (see below), whose sum is σ = 32418144. Its totient is φ = 24013120.

The previous prime is 28065517. The next prime is 28065523. The reversal of 28065521 is 12556082.

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 28065521 - 2² = 28065517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28065523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74855 + ... + 75228.

It is an arithmetic number, because the mean of its divisors is an integer number (4052268).

Almost surely, 2^28065521 is an apocalyptic number.

It is an amenable number.

28065521 is a deficient number, since it is larger than the sum of its proper divisors (4352623).

28065521 is a wasteful number, since it uses less digits than its factorization.

28065521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150111.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 28065521 is about 5297.6901570401. The cubic root of 28065521 is about 303.8955702305.

The spelling of 28065521 in words is "twenty-eight million, sixty-five thousand, five hundred twenty-one".