3947885 has 4 divisors (see below), whose sum is σ = 4737468. Its totient is φ = 3158304.

The previous prime is 3947861. The next prime is 3947891. The reversal of 3947885 is 5887493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5887493 = 29 ⋅203017.

It can be written as a sum of positive squares in 2 ways, for example, as 2569609 + 1378276 = 1603^2 + 1174^2 .

It is a cyclic number.

It is not a de Polignac number, because 3947885 - 2¹⁸ = 3685741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 394784 + ... + 394793.

It is an arithmetic number, because the mean of its divisors is an integer number (1184367).

Almost surely, 2^3947885 is an apocalyptic number.

It is an amenable number.

3947885 is a deficient number, since it is larger than the sum of its proper divisors (789583).

3947885 is an equidigital number, since it uses as much as digits as its factorization.

3947885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789582.

The product of its digits is 241920, while the sum is 44.

The square root of 3947885 is about 1986.9285341954. The cubic root of 3947885 is about 158.0476943020.

The spelling of 3947885 in words is "three million, nine hundred forty-seven thousand, eight hundred eighty-five".