65716561 has 2 divisors, whose sum is σ = 65716562. Its totient is φ = 65716560.

The previous prime is 65716549. The next prime is 65716579. The reversal of 65716561 is 16561756.

65716561 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., 58614336 + 7102225 = 7656^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 65716561 - 2¹³ = 65708369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65716561.

It is not a weakly prime, because it can be changed into another prime (65716591) 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, 32858280 + 32858281.

It is an arithmetic number, because the mean of its divisors is an integer number (32858281).

Almost surely, 2^65716561 is an apocalyptic number.

It is an amenable number.

65716561 is a deficient number, since it is larger than the sum of its proper divisors (1).

65716561 is an equidigital number, since it uses as much as digits as its factorization.

65716561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 37.

The square root of 65716561 is about 8106.5751708104. The cubic root of 65716561 is about 403.5446643503.

The spelling of 65716561 in words is "sixty-five million, seven hundred sixteen thousand, five hundred sixty-one".