206340456091909 has 2 divisors, whose sum is σ = 206340456091910. Its totient is φ = 206340456091908.

The previous prime is 206340456091897. The next prime is 206340456091919. The reversal of 206340456091909 is 909190654043602.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 194442247505025 + 11898208586884 = 13944255^2 + 3449378^2 .

It is a cyclic number.

It is not a de Polignac number, because 206340456091909 - 2¹¹ = 206340456089861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206340456091919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103170228045954 + 103170228045955.

It is an arithmetic number, because the mean of its divisors is an integer number (103170228045955).

Almost surely, 2^{206340456091909} is an apocalyptic number.

It is an amenable number.

206340456091909 is a deficient number, since it is larger than the sum of its proper divisors (1).

206340456091909 is an equidigital number, since it uses as much as digits as its factorization.

206340456091909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12597120, while the sum is 58.

The spelling of 206340456091909 in words is "two hundred six trillion, three hundred forty billion, four hundred fifty-six million, ninety-one thousand, nine hundred nine".