3866639 has 8 divisors (see below), whose sum is σ = 4509600. Its totient is φ = 3313968.

The previous prime is 3866627. The next prime is 3866647. The reversal of 3866639 is 9366683.

It is not a de Polignac number, because 3866639 - 2⁴ = 3866623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3866596 and 3866605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3866609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5294 + ... + 5979.

It is an arithmetic number, because the mean of its divisors is an integer number (563700).

Almost surely, 2^3866639 is an apocalyptic number.

3866639 is a deficient number, since it is larger than the sum of its proper divisors (642961).

3866639 is an equidigital number, since it uses as much as digits as its factorization.

3866639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11294 (or 11280 counting only the distinct ones).

The product of its digits is 139968, while the sum is 41.

The square root of 3866639 is about 1966.3771255789. The cubic root of 3866639 is about 156.9559831708.

The spelling of 3866639 in words is "three million, eight hundred sixty-six thousand, six hundred thirty-nine".