3991207009 has 2 divisors, whose sum is σ = 3991207010. Its totient is φ = 3991207008.

The previous prime is 3991206929. The next prime is 3991207021. The reversal of 3991207009 is 9007021993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2211632784 + 1779574225 = 47028^2 + 42185^2 .

It is a cyclic number.

It is not a de Polignac number, because 3991207009 - 2¹⁷ = 3991075937 is a prime.

It is not a weakly prime, because it can be changed into another prime (3991202009) 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 as a sum of consecutive naturals, namely, 1995603504 + 1995603505.

It is an arithmetic number, because the mean of its divisors is an integer number (1995603505).

Almost surely, 2^3991207009 is an apocalyptic number.

It is an amenable number.

3991207009 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991207009 is an equidigital number, since it uses as much as digits as its factorization.

3991207009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 3991207009 is about 63176.0002611751. Note that the first 3 decimals coincide. The cubic root of 3991207009 is about 1586.2370316858.

The spelling of 3991207009 in words is "three billion, nine hundred ninety-one million, two hundred seven thousand, nine".