397996813 has 2 divisors, whose sum is σ = 397996814. Its totient is φ = 397996812.

The previous prime is 397996801. The next prime is 397996849. The reversal of 397996813 is 318699793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210772324 + 187224489 = 14518^2 + 13683^2 .

It is an emirp because it is prime and its reverse (318699793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 397996813 - 2²⁵ = 364442381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397996873) 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, 198998406 + 198998407.

It is an arithmetic number, because the mean of its divisors is an integer number (198998407).

Almost surely, 2^397996813 is an apocalyptic number.

It is an amenable number.

397996813 is a deficient number, since it is larger than the sum of its proper divisors (1).

397996813 is an equidigital number, since it uses as much as digits as its factorization.

397996813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2204496, while the sum is 55.

The square root of 397996813 is about 19949.8574681625. The cubic root of 397996813 is about 735.5742734501.

The spelling of 397996813 in words is "three hundred ninety-seven million, nine hundred ninety-six thousand, eight hundred thirteen".