9161819857 has 2 divisors, whose sum is σ = 9161819858. Its totient is φ = 9161819856.

The previous prime is 9161819827. The next prime is 9161819869. The reversal of 9161819857 is 7589181619.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7512728976 + 1649090881 = 86676^2 + 40609^2 .

It is an emirp because it is prime and its reverse (7589181619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9161819857 - 2¹¹ = 9161817809 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9161819798 and 9161819807.

It is not a weakly prime, because it can be changed into another prime (9161819827) 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, 4580909928 + 4580909929.

It is an arithmetic number, because the mean of its divisors is an integer number (4580909929).

Almost surely, 2^9161819857 is an apocalyptic number.

It is an amenable number.

9161819857 is a deficient number, since it is larger than the sum of its proper divisors (1).

9161819857 is an equidigital number, since it uses as much as digits as its factorization.

9161819857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 55.

The square root of 9161819857 is about 95717.3957909428. The cubic root of 9161819857 is about 2092.4764686818.

The spelling of 9161819857 in words is "nine billion, one hundred sixty-one million, eight hundred nineteen thousand, eight hundred fifty-seven".