999998981640361 has 2 divisors, whose sum is σ = 999998981640362. Its totient is φ = 999998981640360.

The previous prime is 999998981640343. The next prime is 999998981640383. The reversal of 999998981640361 is 163046189899999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 987333034484736 + 12665947155625 = 31421856^2 + 3558925^2 .

It is a cyclic number.

It is not a de Polignac number, because 999998981640361 - 2¹⁷ = 999998981509289 is a prime.

It is the 31622761-st Hogben number.

It is not a weakly prime, because it can be changed into another prime (999998981644361) by changing a digit.

It is a nontrivial repunit in base 31622760.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999490820180 + 499999490820181.

It is an arithmetic number, because the mean of its divisors is an integer number (499999490820181).

Almost surely, 2^{999998981640361} is an apocalyptic number.

It is an amenable number.

999998981640361 is a deficient number, since it is larger than the sum of its proper divisors (1).

999998981640361 is an equidigital number, since it uses as much as digits as its factorization.

999998981640361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14693280768, while the sum is 91.

The spelling of 999998981640361 in words is "nine hundred ninety-nine trillion, nine hundred ninety-eight billion, nine hundred eighty-one million, six hundred forty thousand, three hundred sixty-one".