3656681 has 4 divisors (see below), whose sum is σ = 4179072. Its totient is φ = 3134292.

The previous prime is 3656669. The next prime is 3656689. The reversal of 3656681 is 1866563.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1866563 = 233 ⋅8011.

It is not a de Polignac number, because 3656681 - 2⁶ = 3656617 is a prime.

It is a super-2 number, since 2×3656681² = 26742631871522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3656689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261185 + ... + 261198.

It is an arithmetic number, because the mean of its divisors is an integer number (1044768).

Almost surely, 2^3656681 is an apocalyptic number.

It is an amenable number.

3656681 is a deficient number, since it is larger than the sum of its proper divisors (522391).

3656681 is an equidigital number, since it uses as much as digits as its factorization.

3656681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522390.

The product of its digits is 25920, while the sum is 35.

The square root of 3656681 is about 1912.2450156818. The cubic root of 3656681 is about 154.0620568473.

The spelling of 3656681 in words is "three million, six hundred fifty-six thousand, six hundred eighty-one".