1908320643 has 6 divisors (see below), whose sum is σ = 2756463164. Its totient is φ = 1272213756.

The previous prime is 1908320627. The next prime is 1908320647. The reversal of 1908320643 is 3460238091.

1908320643 is a `hidden beast` number, since 1 + 9 + 0 + 8 + 3 + 2 + 0 + 643 = 666.

It is not a de Polignac number, because 1908320643 - 2⁴ = 1908320627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1908320598 and 1908320607.

It is not an unprimeable number, because it can be changed into a prime (1908320647) 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 in 5 ways as a sum of consecutive naturals, for example, 106017805 + ... + 106017822.

Almost surely, 2^1908320643 is an apocalyptic number.

1908320643 is a deficient number, since it is larger than the sum of its proper divisors (848142521).

1908320643 is a wasteful number, since it uses less digits than its factorization.

1908320643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212035633 (or 212035630 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 1908320643 is about 43684.3294901043. The cubic root of 1908320643 is about 1240.3677029106.

The spelling of 1908320643 in words is "one billion, nine hundred eight million, three hundred twenty thousand, six hundred forty-three".