7081691909 has 2 divisors, whose sum is σ = 7081691910. Its totient is φ = 7081691908.

The previous prime is 7081691899. The next prime is 7081691977. The reversal of 7081691909 is 9091961807.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6359265025 + 722426884 = 79745^2 + 26878^2 .

It is a cyclic number.

It is not a de Polignac number, because 7081691909 - 2¹⁶ = 7081626373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7081690909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3540845954 + 3540845955.

It is an arithmetic number, because the mean of its divisors is an integer number (3540845955).

Almost surely, 2^7081691909 is an apocalyptic number.

It is an amenable number.

7081691909 is a deficient number, since it is larger than the sum of its proper divisors (1).

7081691909 is an equidigital number, since it uses as much as digits as its factorization.

7081691909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 50.

The square root of 7081691909 is about 84152.7890743973. The cubic root of 7081691909 is about 1920.3438971853.

The spelling of 7081691909 in words is "seven billion, eighty-one million, six hundred ninety-one thousand, nine hundred nine".