194959867616809 has 9 divisors (see below), whose sum is σ = 201452214736119. Its totient is φ = 188670420745080.

The previous prime is 194959867616771. The next prime is 194959867616849. The reversal of 194959867616809 is 908616768959491.

The square root of 194959867616809 is 13962803.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 194732451225 + 194765135165584 = 441285^2 + 13955828^2 .

It is not a de Polignac number, because 194959867616809 - 2³¹ = 194957720133161 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 194959867616809.

It is not an unprimeable number, because it can be changed into a prime (194959867616849) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 432621687 + ... + 433072099.

Almost surely, 2^{194959867616809} is an apocalyptic number.

194959867616809 is the 13962803-rd square number.

194959867616809 is the 6981402-nd centered octagonal number.

It is an amenable number.

194959867616809 is a deficient number, since it is larger than the sum of its proper divisors (6492347119310).

194959867616809 is an frugal number, since it uses more digits than its factorization.

194959867616809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900888 (or 450444 counting only the distinct ones).

The product of its (nonzero) digits is 12697896960, while the sum is 88.

The spelling of 194959867616809 in words is "one hundred ninety-four trillion, nine hundred fifty-nine billion, eight hundred sixty-seven million, six hundred sixteen thousand, eight hundred nine".