196809181 has 2 divisors, whose sum is σ = 196809182. Its totient is φ = 196809180.

The previous prime is 196809169. The next prime is 196809199. The reversal of 196809181 is 181908691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 193460281 + 3348900 = 13909^2 + 1830^2 .

It is an emirp because it is prime and its reverse (181908691) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 181608961 and 169806181.

It is a cyclic number.

It is not a de Polignac number, because 196809181 - 2²¹ = 194712029 is a prime.

It is a super-2 number, since 2×196809181² = 77467707451781522, which contains 22 as substring.

It is a zygodrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (196809101) 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 as a sum of consecutive naturals, namely, 98404590 + 98404591.

It is an arithmetic number, because the mean of its divisors is an integer number (98404591).

Almost surely, 2^196809181 is an apocalyptic number.

It is an amenable number.

196809181 is a deficient number, since it is larger than the sum of its proper divisors (1).

196809181 is an equidigital number, since it uses as much as digits as its factorization.

196809181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 43.

The square root of 196809181 is about 14028.8695553134. The cubic root of 196809181 is about 581.6768565888.

The spelling of 196809181 in words is "one hundred ninety-six million, eight hundred nine thousand, one hundred eighty-one".