3861905 has 4 divisors (see below), whose sum is σ = 4634292. Its totient is φ = 3089520.

The previous prime is 3861899. The next prime is 3861911. The reversal of 3861905 is 5091683.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5091683 = 661 ⋅7703.

It is an interprime number because it is at equal distance from previous prime (3861899) and next prime (3861911).

It can be written as a sum of positive squares in 2 ways, for example, as 1635841 + 2226064 = 1279^2 + 1492^2 .

It is not a de Polignac number, because 3861905 - 2⁴ = 3861889 is a prime.

It is a Duffinian number.

It is a Curzon 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, 386186 + ... + 386195.

It is an arithmetic number, because the mean of its divisors is an integer number (1158573).

Almost surely, 2^3861905 is an apocalyptic number.

It is an amenable number.

3861905 is a deficient number, since it is larger than the sum of its proper divisors (772387).

3861905 is an equidigital number, since it uses as much as digits as its factorization.

3861905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772386.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 3861905 is about 1965.1730203725. The cubic root of 3861905 is about 156.8919022756.

The spelling of 3861905 in words is "three million, eight hundred sixty-one thousand, nine hundred five".