209454336761 has 2 divisors, whose sum is σ = 209454336762. Its totient is φ = 209454336760.

The previous prime is 209454336743. The next prime is 209454336809. The reversal of 209454336761 is 167633454902.

209454336761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209415149161 + 39187600 = 457619^2 + 6260^2 .

It is a cyclic number.

It is not a de Polignac number, because 209454336761 - 2²⁶ = 209387227897 is a prime.

It is a super-2 number, since 2×209454336761² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (209454336061) 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, 104727168380 + 104727168381.

It is an arithmetic number, because the mean of its divisors is an integer number (104727168381).

Almost surely, 2^209454336761 is an apocalyptic number.

It is an amenable number.

209454336761 is a deficient number, since it is larger than the sum of its proper divisors (1).

209454336761 is an equidigital number, since it uses as much as digits as its factorization.

209454336761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3265920, while the sum is 50.

The spelling of 209454336761 in words is "two hundred nine billion, four hundred fifty-four million, three hundred thirty-six thousand, seven hundred sixty-one".