9876188561 has 2 divisors, whose sum is σ = 9876188562. Its totient is φ = 9876188560.

The previous prime is 9876188557. The next prime is 9876188563. The reversal of 9876188561 is 1658816789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6359105536 + 3517083025 = 79744^2 + 59305^2 .

It is a cyclic number.

It is not a de Polignac number, because 9876188561 - 2² = 9876188557 is a prime.

It is a Sophie Germain prime.

Together with 9876188563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9876188561.

It is not a weakly prime, because it can be changed into another prime (9876188563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4938094280 + 4938094281.

It is an arithmetic number, because the mean of its divisors is an integer number (4938094281).

Almost surely, 2^9876188561 is an apocalyptic number.

It is an amenable number.

9876188561 is a deficient number, since it is larger than the sum of its proper divisors (1).

9876188561 is an equidigital number, since it uses as much as digits as its factorization.

9876188561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5806080, while the sum is 59.

The square root of 9876188561 is about 99379.0146912315. The cubic root of 9876188561 is about 2145.5062847535.

The spelling of 9876188561 in words is "nine billion, eight hundred seventy-six million, one hundred eighty-eight thousand, five hundred sixty-one".