396666691 has 2 divisors, whose sum is σ = 396666692. Its totient is φ = 396666690.

The previous prime is 396666689. The next prime is 396666703. The reversal of 396666691 is 196666693.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 396666691 - 2¹ = 396666689 is a prime.

Together with 396666689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (396666631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198333345 + 198333346.

It is an arithmetic number, because the mean of its divisors is an integer number (198333346).

Almost surely, 2^396666691 is an apocalyptic number.

396666691 is a deficient number, since it is larger than the sum of its proper divisors (1).

396666691 is an equidigital number, since it uses as much as digits as its factorization.

396666691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1889568, while the sum is 52.

The square root of 396666691 is about 19916.4929392702. The cubic root of 396666691 is about 734.7539188851.

The spelling of 396666691 in words is "three hundred ninety-six million, six hundred sixty-six thousand, six hundred ninety-one".