6506651561 has 2 divisors, whose sum is σ = 6506651562. Its totient is φ = 6506651560.

The previous prime is 6506651537. The next prime is 6506651633. The reversal of 6506651561 is 1651566056.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6502003225 + 4648336 = 80635^2 + 2156^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6506651561 is a prime.

It is not a weakly prime, because it can be changed into another prime (6506657561) 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, 3253325780 + 3253325781.

It is an arithmetic number, because the mean of its divisors is an integer number (3253325781).

Almost surely, 2^6506651561 is an apocalyptic number.

It is an amenable number.

6506651561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6506651561 is an equidigital number, since it uses as much as digits as its factorization.

6506651561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162000, while the sum is 41.

The square root of 6506651561 is about 80663.8181652716. The cubic root of 6506651561 is about 1866.8919517885.

The spelling of 6506651561 in words is "six billion, five hundred six million, six hundred fifty-one thousand, five hundred sixty-one".