194661063721 has 2 divisors, whose sum is σ = 194661063722. Its totient is φ = 194661063720.

The previous prime is 194661063643. The next prime is 194661063731. The reversal of 194661063721 is 127360166491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162621853696 + 32039210025 = 403264^2 + 178995^2 .

It is a cyclic number.

It is not a de Polignac number, because 194661063721 - 2⁷ = 194661063593 is a prime.

It is not a weakly prime, because it can be changed into another prime (194661063731) 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, 97330531860 + 97330531861.

It is an arithmetic number, because the mean of its divisors is an integer number (97330531861).

Almost surely, 2^194661063721 is an apocalyptic number.

It is an amenable number.

194661063721 is a deficient number, since it is larger than the sum of its proper divisors (1).

194661063721 is an equidigital number, since it uses as much as digits as its factorization.

194661063721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 46.

The spelling of 194661063721 in words is "one hundred ninety-four billion, six hundred sixty-one million, sixty-three thousand, seven hundred twenty-one".