208165668988481 has 4 divisors (see below), whose sum is σ = 219121756830000. Its totient is φ = 197209581146964.

The previous prime is 208165668988477. The next prime is 208165668988547. The reversal of 208165668988481 is 184889866561802.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 208165668988481 - 2² = 208165668988477 is a prime.

It is a super-2 number, since 2×208165668988481² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 208165668988396 and 208165668988405.

It is not an unprimeable number, because it can be changed into a prime (208165668988181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5478043920731 + ... + 5478043920768.

It is an arithmetic number, because the mean of its divisors is an integer number (54780439207500).

Almost surely, 2^{208165668988481} is an apocalyptic number.

It is an amenable number.

208165668988481 is a deficient number, since it is larger than the sum of its proper divisors (10956087841519).

208165668988481 is a wasteful number, since it uses less digits than its factorization.

208165668988481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10956087841518.

The product of its (nonzero) digits is 2548039680, while the sum is 80.

The spelling of 208165668988481 in words is "two hundred eight trillion, one hundred sixty-five billion, six hundred sixty-eight million, nine hundred eighty-eight thousand, four hundred eighty-one".