6641012561 has 2 divisors, whose sum is σ = 6641012562. Its totient is φ = 6641012560.

The previous prime is 6641012513. The next prime is 6641012611. The reversal of 6641012561 is 1652101466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4727387536 + 1913625025 = 68756^2 + 43745^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6641012561 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6641014561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320506280 + 3320506281.

It is an arithmetic number, because the mean of its divisors is an integer number (3320506281).

Almost surely, 2^6641012561 is an apocalyptic number.

It is an amenable number.

6641012561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6641012561 is an equidigital number, since it uses as much as digits as its factorization.

6641012561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 6641012561 is about 81492.4079960827. The cubic root of 6641012561 is about 1879.6548107178.

The spelling of 6641012561 in words is "six billion, six hundred forty-one million, twelve thousand, five hundred sixty-one".