9999995861 has 2 divisors, whose sum is σ = 9999995862. Its totient is φ = 9999995860.

The previous prime is 9999995813. The next prime is 9999995869. The reversal of 9999995861 is 1685999999.

9999995861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9973018225 + 26977636 = 99865^2 + 5194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9999995861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9999995869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999997930 + 4999997931.

It is an arithmetic number, because the mean of its divisors is an integer number (4999997931).

Almost surely, 2^9999995861 is an apocalyptic number.

It is an amenable number.

9999995861 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999995861 is an equidigital number, since it uses as much as digits as its factorization.

9999995861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127545840, while the sum is 74.

The square root of 9999995861 is about 99999.9793049979. The cubic root of 9999995861 is about 2154.4343927917.

The spelling of 9999995861 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-five thousand, eight hundred sixty-one".