3686391 has 20 divisors (see below), whose sum is σ = 5593104. Its totient is φ = 2419200.

The previous prime is 3686387. The next prime is 3686401. The reversal of 3686391 is 1936863.

It is a happy number.

It is not a de Polignac number, because 3686391 - 2² = 3686387 is a prime.

3686391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3686321) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5431 + ... + 6071.

Almost surely, 2^3686391 is an apocalyptic number.

3686391 is a deficient number, since it is larger than the sum of its proper divisors (1906713).

3686391 is an equidigital number, since it uses as much as digits as its factorization.

3686391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 715 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 3686391 is about 1919.9976562486. The cubic root of 3686391 is about 154.4781758220.

It can be divided in two parts, 36863 and 91, that multiplied together give a palindrome (3354533).

The spelling of 3686391 in words is "three million, six hundred eighty-six thousand, three hundred ninety-one".