194863909 has 2 divisors, whose sum is σ = 194863910. Its totient is φ = 194863908.

The previous prime is 194863901. The next prime is 194863957. The reversal of 194863909 is 909368491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192598884 + 2265025 = 13878^2 + 1505^2 .

It is an emirp because it is prime and its reverse (909368491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194863909 - 2³ = 194863901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194863901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97431954 + 97431955.

It is an arithmetic number, because the mean of its divisors is an integer number (97431955).

Almost surely, 2^194863909 is an apocalyptic number.

It is an amenable number.

194863909 is a deficient number, since it is larger than the sum of its proper divisors (1).

194863909 is an equidigital number, since it uses as much as digits as its factorization.

194863909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 194863909 is about 13959.3663538142. The cubic root of 194863909 is about 579.7540663633.

The spelling of 194863909 in words is "one hundred ninety-four million, eight hundred sixty-three thousand, nine hundred nine".