396991985329 has 9 divisors (see below), whose sum is σ = 408035446497. Its totient is φ = 386239789584.

The previous prime is 396991985321. The next prime is 396991985333. The reversal of 396991985329 is 923589199693.

The square root of 396991985329 is 630073.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 194988480625 + 202003504704 = 441575^2 + 449448^2 .

It is not a de Polignac number, because 396991985329 - 2³ = 396991985321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (396991985321) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 23304187 + ... + 23321215.

It is an arithmetic number, because the mean of its divisors is an integer number (45337271833).

Almost surely, 2^396991985329 is an apocalyptic number.

396991985329 is the 630073-rd square number.

396991985329 is the 315037-th centered octagonal number.

It is an amenable number.

396991985329 is a deficient number, since it is larger than the sum of its proper divisors (11043461168).

396991985329 is an frugal number, since it uses more digits than its factorization.

396991985329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34132 (or 17066 counting only the distinct ones).

The product of its digits is 255091680, while the sum is 73.

The spelling of 396991985329 in words is "three hundred ninety-six billion, nine hundred ninety-one million, nine hundred eighty-five thousand, three hundred twenty-nine".