3866581 has 2 divisors, whose sum is σ = 3866582. Its totient is φ = 3866580.

The previous prime is 3866543. The next prime is 3866609. The reversal of 3866581 is 1856683.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3837681 + 28900 = 1959^2 + 170^2 .

It is a cyclic number.

It is not a de Polignac number, because 3866581 - 2⁷ = 3866453 is a prime.

It is a super-2 number, since 2×3866581² = 29900897259122, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3866581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3866081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1933290 + 1933291.

It is an arithmetic number, because the mean of its divisors is an integer number (1933291).

Almost surely, 2^3866581 is an apocalyptic number.

It is an amenable number.

3866581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3866581 is an equidigital number, since it uses as much as digits as its factorization.

3866581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 37.

The square root of 3866581 is about 1966.3623775896. The cubic root of 3866581 is about 156.9551983814.

The spelling of 3866581 in words is "three million, eight hundred sixty-six thousand, five hundred eighty-one".