4005691 has 2 divisors, whose sum is σ = 4005692. Its totient is φ = 4005690.

The previous prime is 4005653. The next prime is 4005733. The reversal of 4005691 is 1965004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4005691 - 2¹⁵ = 3972923 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (4005091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2002845 + 2002846.

It is an arithmetic number, because the mean of its divisors is an integer number (2002846).

Almost surely, 2^4005691 is an apocalyptic number.

4005691 is a deficient number, since it is larger than the sum of its proper divisors (1).

4005691 is an equidigital number, since it uses as much as digits as its factorization.

4005691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 4005691 is about 2001.4222443053. The cubic root of 4005691 is about 158.8153520172.

The spelling of 4005691 in words is "four million, five thousand, six hundred ninety-one".