5661661551161 has 12 divisors (see below), whose sum is σ = 7184743045200. Its totient is φ = 4411684325160.

The previous prime is 5661661551109. The next prime is 5661661551163. The reversal of 5661661551161 is 1611551661665.

It is not a de Polignac number, because 5661661551161 - 2¹⁰ = 5661661550137 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (5661661551163) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5252004611 + ... + 5252005688.

It is an arithmetic number, because the mean of its divisors is an integer number (598728587100).

Almost surely, 2^{5661661551161} is an apocalyptic number.

It is an amenable number.

5661661551161 is a deficient number, since it is larger than the sum of its proper divisors (1523081494039).

5661661551161 is a wasteful number, since it uses less digits than its factorization.

5661661551161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10504010324 (or 10504010317 counting only the distinct ones).

The product of its digits is 972000, while the sum is 50.

The spelling of 5661661551161 in words is "five trillion, six hundred sixty-one billion, six hundred sixty-one million, five hundred fifty-one thousand, one hundred sixty-one".