194143561 has 2 divisors, whose sum is σ = 194143562. Its totient is φ = 194143560.

The previous prime is 194143507. The next prime is 194143583. The reversal of 194143561 is 165341491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160503561 + 33640000 = 12669^2 + 5800^2 .

It is a cyclic number.

It is not a de Polignac number, because 194143561 - 2²⁵ = 160589129 is a prime.

It is not a weakly prime, because it can be changed into another prime (194143591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97071780 + 97071781.

It is an arithmetic number, because the mean of its divisors is an integer number (97071781).

Almost surely, 2^194143561 is an apocalyptic number.

It is an amenable number.

194143561 is a deficient number, since it is larger than the sum of its proper divisors (1).

194143561 is an equidigital number, since it uses as much as digits as its factorization.

194143561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 34.

The square root of 194143561 is about 13933.5408636857. The cubic root of 194143561 is about 579.0387973481.

The spelling of 194143561 in words is "one hundred ninety-four million, one hundred forty-three thousand, five hundred sixty-one".