3691 has 2 divisors, whose sum is σ = 3692. Its totient is φ = 3690.

The previous prime is 3677. The next prime is 3697. The reversal of 3691 is 1963.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3691 - 2⁵ = 3659 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (3697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1845 + 1846.

It is an arithmetic number, because the mean of its divisors is an integer number (1846).

2³⁶⁹¹ is an apocalyptic number.

3691 is a deficient number, since it is larger than the sum of its proper divisors (1).

3691 is an equidigital number, since it uses as much as digits as its factorization.

3691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162, while the sum is 19.

The square root of 3691 is about 60.7536007163. The cubic root of 3691 is about 15.4542529042.

Subtracting from 3691 its reverse (1963), we obtain a cube (1728 = 12³).

The spelling of 3691 in words is "three thousand, six hundred ninety-one".