396388991 has 2 divisors, whose sum is σ = 396388992. Its totient is φ = 396388990.

The previous prime is 396388987. The next prime is 396388999. The reversal of 396388991 is 199883693.

It is a weak prime.

It is an emirp because it is prime and its reverse (199883693) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 396388991 - 2² = 396388987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (396388999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198194495 + 198194496.

It is an arithmetic number, because the mean of its divisors is an integer number (198194496).

Almost surely, 2^396388991 is an apocalyptic number.

396388991 is a deficient number, since it is larger than the sum of its proper divisors (1).

396388991 is an equidigital number, since it uses as much as digits as its factorization.

396388991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 56.

The square root of 396388991 is about 19909.5201097364. The cubic root of 396388991 is about 734.5824157048.

The spelling of 396388991 in words is "three hundred ninety-six million, three hundred eighty-eight thousand, nine hundred ninety-one".