999999997764161 has 2 divisors, whose sum is σ = 999999997764162. Its totient is φ = 999999997764160.

The previous prime is 999999997764101. The next prime is 999999997764179. The reversal of 999999997764161 is 161467799999999.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 987779275249936 + 12220722514225 = 31428956^2 + 3495815^2 .

It is an emirp because it is prime and its reverse (161467799999999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999999997764161 - 2⁴² = 995601951253057 is a prime.

It is not a weakly prime, because it can be changed into another prime (999999997764101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999998882080 + 499999998882081.

It is an arithmetic number, because the mean of its divisors is an integer number (499999998882081).

Almost surely, 2^{999999997764161} is an apocalyptic number.

It is an amenable number.

999999997764161 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999997764161 is an equidigital number, since it uses as much as digits as its factorization.

999999997764161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 303737663376, while the sum is 104.

The spelling of 999999997764161 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-seven million, seven hundred sixty-four thousand, one hundred sixty-one".