9915847861 has 2 divisors, whose sum is σ = 9915847862. Its totient is φ = 9915847860.

The previous prime is 9915847847. The next prime is 9915847867. The reversal of 9915847861 is 1687485199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6894146961 + 3021700900 = 83031^2 + 54970^2 .

It is a cyclic number.

It is not a de Polignac number, because 9915847861 - 2¹⁹ = 9915323573 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9915847796 and 9915847805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9915847867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4957923930 + 4957923931.

It is an arithmetic number, because the mean of its divisors is an integer number (4957923931).

Almost surely, 2^9915847861 is an apocalyptic number.

It is an amenable number.

9915847861 is a deficient number, since it is larger than the sum of its proper divisors (1).

9915847861 is an equidigital number, since it uses as much as digits as its factorization.

9915847861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4354560, while the sum is 58.

The square root of 9915847861 is about 99578.3503629177. The cubic root of 9915847861 is about 2148.3743154073.

The spelling of 9915847861 in words is "nine billion, nine hundred fifteen million, eight hundred forty-seven thousand, eight hundred sixty-one".