4000691 has 2 divisors, whose sum is σ = 4000692. Its totient is φ = 4000690.

The previous prime is 4000679. The next prime is 4000693. The reversal of 4000691 is 1960004.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4000691 is a prime.

Together with 4000693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (4000693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2000345 + 2000346.

It is an arithmetic number, because the mean of its divisors is an integer number (2000346).

Almost surely, 2^4000691 is an apocalyptic number.

4000691 is a deficient number, since it is larger than the sum of its proper divisors (1).

4000691 is an equidigital number, since it uses as much as digits as its factorization.

4000691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 4000691 is about 2000.1727425400. The cubic root of 4000691 is about 158.7492454549.

Adding to 4000691 its reverse (1960004), we get a palindrome (5960695).

The spelling of 4000691 in words is "four million, six hundred ninety-one", and thus it is an aban number.