6661560661061 has 2 divisors, whose sum is σ = 6661560661062. Its totient is φ = 6661560661060.

The previous prime is 6661560661043. The next prime is 6661560661081. The reversal of 6661560661061 is 1601660651666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6646161340225 + 15399320836 = 2578015^2 + 124094^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661560661061 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6661560661001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330780330530 + 3330780330531.

It is an arithmetic number, because the mean of its divisors is an integer number (3330780330531).

Almost surely, 2^{6661560661061} is an apocalyptic number.

It is an amenable number.

6661560661061 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661560661061 is an equidigital number, since it uses as much as digits as its factorization.

6661560661061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1399680, while the sum is 50.

The spelling of 6661560661061 in words is "six trillion, six hundred sixty-one billion, five hundred sixty million, six hundred sixty-one thousand, sixty-one".