1920920809 has 2 divisors, whose sum is σ = 1920920810. Its totient is φ = 1920920808.

The previous prime is 1920920803. The next prime is 1920920819. The reversal of 1920920809 is 9080290291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1920893584 + 27225 = 43828^2 + 165^2 .

It is a cyclic number.

It is not a de Polignac number, because 1920920809 - 2³ = 1920920801 is a prime.

It is not a weakly prime, because it can be changed into another prime (1920920801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960460404 + 960460405.

It is an arithmetic number, because the mean of its divisors is an integer number (960460405).

Almost surely, 2^1920920809 is an apocalyptic number.

It is an amenable number.

1920920809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1920920809 is an equidigital number, since it uses as much as digits as its factorization.

1920920809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1920920809 is about 43828.3105880206. The cubic root of 1920920809 is about 1243.0916628249.

The spelling of 1920920809 in words is "one billion, nine hundred twenty million, nine hundred twenty thousand, eight hundred nine".