11661560661109 has 2 divisors, whose sum is σ = 11661560661110. Its totient is φ = 11661560661108.

The previous prime is 11661560661103. The next prime is 11661560661119. The reversal of 11661560661109 is 90116606516611.

It is a happy number.

11661560661109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6246850396900 + 5414710264209 = 2499370^2 + 2326953^2 .

It is an emirp because it is prime and its reverse (90116606516611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11661560661109 - 2³⁵ = 11627200922741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11661560661103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5830780330554 + 5830780330555.

It is an arithmetic number, because the mean of its divisors is an integer number (5830780330555).

Almost surely, 2^{11661560661109} is an apocalyptic number.

It is an amenable number.

11661560661109 is a deficient number, since it is larger than the sum of its proper divisors (1).

11661560661109 is an equidigital number, since it uses as much as digits as its factorization.

11661560661109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 49.

The spelling of 11661560661109 in words is "eleven trillion, six hundred sixty-one billion, five hundred sixty million, six hundred sixty-one thousand, one hundred nine".