10561165661 has 4 divisors (see below), whose sum is σ = 10600137024. Its totient is φ = 10522194300.

The previous prime is 10561165621. The next prime is 10561165669. The reversal of 10561165661 is 16656116501.

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.

It is a cyclic number.

It is not a de Polignac number, because 10561165661 - 2³⁰ = 9487423837 is a prime.

It is a super-2 number, since 2×10561165661² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10561165669) 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, 19485275 + ... + 19485816.

It is an arithmetic number, because the mean of its divisors is an integer number (2650034256).

Almost surely, 2^10561165661 is an apocalyptic number.

It is an amenable number.

10561165661 is a deficient number, since it is larger than the sum of its proper divisors (38971363).

10561165661 is an equidigital number, since it uses as much as digits as its factorization.

10561165661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38971362.

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 10561165661 in words is "ten billion, five hundred sixty-one million, one hundred sixty-five thousand, six hundred sixty-one".