5661561105009 has 24 divisors (see below), whose sum is σ = 8671724377992. Its totient is φ = 3547073617920.

The previous prime is 5661561104993. The next prime is 5661561105041. The reversal of 5661561105009 is 9005011651665.

5661561105009 is a `hidden beast` number, since 5 + 66 + 15 + 61 + 10 + 500 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1276285353984 + 4385275751025 = 1129728^2 + 2094105^2 .

It is not a de Polignac number, because 5661561105009 - 2⁴ = 5661561104993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (5661561105049) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27388612 + ... + 27594549.

It is an arithmetic number, because the mean of its divisors is an integer number (361321849083).

Almost surely, 2^{5661561105009} is an apocalyptic number.

It is an amenable number.

5661561105009 is a deficient number, since it is larger than the sum of its proper divisors (3010163272983).

5661561105009 is a wasteful number, since it uses less digits than its factorization.

5661561105009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54983857 (or 54983854 counting only the distinct ones).

The product of its (nonzero) digits is 243000, while the sum is 45.

The spelling of 5661561105009 in words is "five trillion, six hundred sixty-one billion, five hundred sixty-one million, one hundred five thousand, nine".