3906785 has 4 divisors (see below), whose sum is σ = 4688148. Its totient is φ = 3125424.

The previous prime is 3906779. The next prime is 3906797. The reversal of 3906785 is 5876093.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5876093 = 271 ⋅21683.

It can be written as a sum of positive squares in 2 ways, for example, as 1317904 + 2588881 = 1148^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 3906785 - 2⁴ = 3906769 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 390674 + ... + 390683.

It is an arithmetic number, because the mean of its divisors is an integer number (1172037).

Almost surely, 2^3906785 is an apocalyptic number.

It is an amenable number.

3906785 is a deficient number, since it is larger than the sum of its proper divisors (781363).

3906785 is an equidigital number, since it uses as much as digits as its factorization.

3906785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781362.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 3906785 is about 1976.5588784552. The cubic root of 3906785 is about 157.4973208581.

It can be divided in two parts, 390 and 6785, that multiplied together give a triangular number (2646150 = T₂₃₀₀).

The spelling of 3906785 in words is "three million, nine hundred six thousand, seven hundred eighty-five".