395664991 has 2 divisors, whose sum is σ = 395664992. Its totient is φ = 395664990.

The previous prime is 395664979. The next prime is 395665019. The reversal of 395664991 is 199466593.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 395664991 - 2⁵ = 395664959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (395664931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197832495 + 197832496.

It is an arithmetic number, because the mean of its divisors is an integer number (197832496).

Almost surely, 2^395664991 is an apocalyptic number.

395664991 is a deficient number, since it is larger than the sum of its proper divisors (1).

395664991 is an equidigital number, since it uses as much as digits as its factorization.

395664991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1574640, while the sum is 52.

The square root of 395664991 is about 19891.3295432960. The cubic root of 395664991 is about 734.1349076521.

The spelling of 395664991 in words is "three hundred ninety-five million, six hundred sixty-four thousand, nine hundred ninety-one".