11561616066 has 192 divisors, whose sum is σ = 31531852800. Its totient is φ = 2749887360.

The previous prime is 11561616023. The next prime is 11561616097. The reversal of 11561616066 is 66061616511.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9182545 + ... + 9183803.

It is an arithmetic number, because the mean of its divisors is an integer number (164228400).

Almost surely, 2^11561616066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11561616066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15765926400).

11561616066 is an abundant number, since it is smaller than the sum of its proper divisors (19970236734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11561616066 is a wasteful number, since it uses less digits than its factorization.

11561616066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445 (or 1434 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 11561616066 in words is "eleven billion, five hundred sixty-one million, six hundred sixteen thousand, sixty-six".