3909521 has 8 divisors (see below), whose sum is σ = 4874304. Its totient is φ = 3046320.

The previous prime is 3909509. The next prime is 3909523. The reversal of 3909521 is 1259093.

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 3909521 - 2¹⁰ = 3908497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3909523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25310 + ... + 25463.

It is an arithmetic number, because the mean of its divisors is an integer number (609288).

Almost surely, 2^3909521 is an apocalyptic number.

It is an amenable number.

3909521 is a deficient number, since it is larger than the sum of its proper divisors (964783).

3909521 is a wasteful number, since it uses less digits than its factorization.

3909521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50791.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 3909521 is about 1977.2508692627. The cubic root of 3909521 is about 157.5340784577.

The spelling of 3909521 in words is "three million, nine hundred nine thousand, five hundred twenty-one".