66112561 has 2 divisors, whose sum is σ = 66112562. Its totient is φ = 66112560.

The previous prime is 66112537. The next prime is 66112589. The reversal of 66112561 is 16521166.

66112561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (66112589) can be obtained adding 66112561 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65302561 + 810000 = 8081^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 66112561 - 2⁷ = 66112433 is a prime.

It is not a weakly prime, because it can be changed into another prime (66112531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33056280 + 33056281.

It is an arithmetic number, because the mean of its divisors is an integer number (33056281).

Almost surely, 2^66112561 is an apocalyptic number.

It is an amenable number.

66112561 is a deficient number, since it is larger than the sum of its proper divisors (1).

66112561 is an equidigital number, since it uses as much as digits as its factorization.

66112561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

The square root of 66112561 is about 8130.9631040855. The cubic root of 66112561 is about 404.3536119938.

The spelling of 66112561 in words is "sixty-six million, one hundred twelve thousand, five hundred sixty-one".