9681909561 has 16 divisors (see below), whose sum is σ = 14345593920. Its totient is φ = 6453695520.

The previous prime is 9681909551. The next prime is 9681909563. The reversal of 9681909561 is 1659091869.

9681909561 is a `hidden beast` number, since 9 + 68 + 19 + 0 + 9 + 561 = 666.

It is not a de Polignac number, because 9681909561 - 2¹¹ = 9681907513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9681909498 and 9681909507.

It is not an unprimeable number, because it can be changed into a prime (9681909563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209026 + ... + 251108.

It is an arithmetic number, because the mean of its divisors is an integer number (896599620).

Almost surely, 2^9681909561 is an apocalyptic number.

It is an amenable number.

9681909561 is a deficient number, since it is larger than the sum of its proper divisors (4663684359).

9681909561 is a wasteful number, since it uses less digits than its factorization.

9681909561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50613 (or 50607 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 54.

The square root of 9681909561 is about 98396.6948682729. The cubic root of 9681909561 is about 2131.3446042966.

The spelling of 9681909561 in words is "nine billion, six hundred eighty-one million, nine hundred nine thousand, five hundred sixty-one".