194564861 has 2 divisors, whose sum is σ = 194564862. Its totient is φ = 194564860.

The previous prime is 194564789. The next prime is 194564893. The reversal of 194564861 is 168465491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127012900 + 67551961 = 11270^2 + 8219^2 .

It is an emirp because it is prime and its reverse (168465491) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194564861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194567861) 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, 97282430 + 97282431.

It is an arithmetic number, because the mean of its divisors is an integer number (97282431).

Almost surely, 2^194564861 is an apocalyptic number.

It is an amenable number.

194564861 is a deficient number, since it is larger than the sum of its proper divisors (1).

194564861 is an equidigital number, since it uses as much as digits as its factorization.

194564861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 44.

The square root of 194564861 is about 13948.6508666609. The cubic root of 194564861 is about 579.4573412278.

The spelling of 194564861 in words is "one hundred ninety-four million, five hundred sixty-four thousand, eight hundred sixty-one".