208090077809 has 4 divisors (see below), whose sum is σ = 213714134004. Its totient is φ = 202466021616.

The previous prime is 208090077781. The next prime is 208090077823. The reversal of 208090077809 is 908770090802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 158048387809 + 50041690000 = 397553^2 + 223700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208090077809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208090077869) 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 3 ways as a sum of consecutive naturals, for example, 2812028042 + ... + 2812028115.

It is an arithmetic number, because the mean of its divisors is an integer number (53428533501).

Almost surely, 2^208090077809 is an apocalyptic number.

It is an amenable number.

208090077809 is a deficient number, since it is larger than the sum of its proper divisors (5624056195).

208090077809 is an equidigital number, since it uses as much as digits as its factorization.

208090077809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5624056194.

The product of its (nonzero) digits is 508032, while the sum is 50.

The spelling of 208090077809 in words is "two hundred eight billion, ninety million, seventy-seven thousand, eight hundred nine".