1643904296 has 16 divisors (see below), whose sum is σ = 3101955540. Its totient is φ = 816716160.

The previous prime is 1643904293. The next prime is 1643904329. The reversal of 1643904296 is 6924093461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1598880196 + 45024100 = 39986^2 + 6710^2 .

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1643904293) 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 in 3 ways as a sum of consecutive naturals, for example, 653165 + ... + 655676.

Almost surely, 2^1643904296 is an apocalyptic number.

It is an amenable number.

1643904296 is a deficient number, since it is larger than the sum of its proper divisors (1458051244).

1643904296 is a wasteful number, since it uses less digits than its factorization.

1643904296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1309004 (or 1309000 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 44.

The square root of 1643904296 is about 40545.0896657043. The cubic root of 1643904296 is about 1180.2087861908.

The spelling of 1643904296 in words is "one billion, six hundred forty-three million, nine hundred four thousand, two hundred ninety-six".