206809173919 has 2 divisors, whose sum is σ = 206809173920. Its totient is φ = 206809173918.

The previous prime is 206809173803. The next prime is 206809173941. The reversal of 206809173919 is 919371908602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206809173919 is a prime.

It is a super-2 number, since 2×206809173919² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 206809173919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206809173419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103404586959 + 103404586960.

It is an arithmetic number, because the mean of its divisors is an integer number (103404586960).

Almost surely, 2^206809173919 is an apocalyptic number.

206809173919 is a deficient number, since it is larger than the sum of its proper divisors (1).

206809173919 is an equidigital number, since it uses as much as digits as its factorization.

206809173919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The spelling of 206809173919 in words is "two hundred six billion, eight hundred nine million, one hundred seventy-three thousand, nine hundred nineteen".