65767561 has 2 divisors, whose sum is σ = 65767562. Its totient is φ = 65767560.

The previous prime is 65767553. The next prime is 65767571. The reversal of 65767561 is 16576756.

65767561 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., 46240000 + 19527561 = 6800^2 + 4419^2 .

It is a cyclic number.

It is not a de Polignac number, because 65767561 - 2³ = 65767553 is a prime.

It is not a weakly prime, because it can be changed into another prime (65767571) 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, 32883780 + 32883781.

It is an arithmetic number, because the mean of its divisors is an integer number (32883781).

Almost surely, 2^65767561 is an apocalyptic number.

It is an amenable number.

65767561 is a deficient number, since it is larger than the sum of its proper divisors (1).

65767561 is an equidigital number, since it uses as much as digits as its factorization.

65767561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 264600, while the sum is 43.

The square root of 65767561 is about 8109.7201554678. The cubic root of 65767561 is about 403.6490289928.

The spelling of 65767561 in words is "sixty-five million, seven hundred sixty-seven thousand, five hundred sixty-one".