9876187561 has 4 divisors (see below), whose sum is σ = 9877626000. Its totient is φ = 9874749124.

The previous prime is 9876187549. The next prime is 9876187567. The reversal of 9876187561 is 1657816789.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1657816789 = 7159 ⋅231571.

It is a cyclic number.

It is not a de Polignac number, because 9876187561 - 2¹⁵ = 9876154793 is a prime.

It is a super-4 number, since 4×9876187561⁴ (a number of 41 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9876187496 and 9876187505.

It is not an unprimeable number, because it can be changed into a prime (9876187567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 708871 + ... + 722668.

It is an arithmetic number, because the mean of its divisors is an integer number (2469406500).

Almost surely, 2^9876187561 is an apocalyptic number.

It is an amenable number.

9876187561 is a deficient number, since it is larger than the sum of its proper divisors (1438439).

9876187561 is a wasteful number, since it uses less digits than its factorization.

9876187561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1438438.

The product of its digits is 5080320, while the sum is 58.

The square root of 9876187561 is about 99379.0096599881. The cubic root of 9876187561 is about 2145.5062123400.

The spelling of 9876187561 in words is "nine billion, eight hundred seventy-six million, one hundred eighty-seven thousand, five hundred sixty-one".