4391209 has 8 divisors (see below), whose sum is σ = 4629960. Its totient is φ = 4158336.

The previous prime is 4391161. The next prime is 4391221. The reversal of 4391209 is 9021934.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1432809 + 2958400 = 1197^2 + 1720^2 .

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 4391209 - 2⁷ = 4391081 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (4391249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109 + ... + 2965.

It is an arithmetic number, because the mean of its divisors is an integer number (578745).

Almost surely, 2^4391209 is an apocalyptic number.

It is an amenable number.

4391209 is a deficient number, since it is larger than the sum of its proper divisors (238751).

4391209 is a wasteful number, since it uses less digits than its factorization.

4391209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2939.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 4391209 is about 2095.5211762232. The cubic root of 4391209 is about 163.7550502492.

It can be divided in two parts, 4391 and 209, that multiplied together give a palindrome (917719).

The spelling of 4391209 in words is "four million, three hundred ninety-one thousand, two hundred nine".