9666315561 has 32 divisors (see below), whose sum is σ = 15221579776. Its totient is φ = 5345082000.

The previous prime is 9666315559. The next prime is 9666315599. The reversal of 9666315561 is 1655136669.

It is not a de Polignac number, because 9666315561 - 2¹ = 9666315559 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9666315561.

It is not an unprimeable number, because it can be changed into a prime (9666315521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 617886 + ... + 633336.

It is an arithmetic number, because the mean of its divisors is an integer number (475674368).

Almost surely, 2^9666315561 is an apocalyptic number.

It is an amenable number.

9666315561 is a deficient number, since it is larger than the sum of its proper divisors (5555264215).

9666315561 is an equidigital number, since it uses as much as digits as its factorization.

9666315561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15554 (or 15492 counting only the distinct ones).

The product of its digits is 874800, while the sum is 48.

The square root of 9666315561 is about 98317.4224692653. The cubic root of 9666315561 is about 2130.1997183181.

The spelling of 9666315561 in words is "nine billion, six hundred sixty-six million, three hundred fifteen thousand, five hundred sixty-one".