66010561 has 2 divisors, whose sum is σ = 66010562. Its totient is φ = 66010560.

The previous prime is 66010559. The next prime is 66010589. The reversal of 66010561 is 16501066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47348161 + 18662400 = 6881^2 + 4320^2 .

It is a cyclic number.

It is not a de Polignac number, because 66010561 - 2¹ = 66010559 is a prime.

Together with 66010559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66010261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33005280 + 33005281.

It is an arithmetic number, because the mean of its divisors is an integer number (33005281).

Almost surely, 2^66010561 is an apocalyptic number.

It is an amenable number.

66010561 is a deficient number, since it is larger than the sum of its proper divisors (1).

66010561 is an equidigital number, since it uses as much as digits as its factorization.

66010561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 66010561 is about 8124.6883632543. The cubic root of 66010561 is about 404.1455562337.

The spelling of 66010561 in words is "sixty-six million, ten thousand, five hundred sixty-one".