3947909 has 4 divisors (see below), whose sum is σ = 4511904. Its totient is φ = 3383916.

The previous prime is 3947903. The next prime is 3947921. The reversal of 3947909 is 9097493.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9097493 = 149 ⋅61057.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3947909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3947903) 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, 281987 + ... + 282000.

It is an arithmetic number, because the mean of its divisors is an integer number (1127976).

Almost surely, 2^3947909 is an apocalyptic number.

It is an amenable number.

3947909 is a deficient number, since it is larger than the sum of its proper divisors (563995).

3947909 is an equidigital number, since it uses as much as digits as its factorization.

3947909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563994.

The product of its (nonzero) digits is 61236, while the sum is 41.

The square root of 3947909 is about 1986.9345736586. The cubic root of 3947909 is about 158.0480145694.

The spelling of 3947909 in words is "three million, nine hundred forty-seven thousand, nine hundred nine".