6506607661 has 2 divisors, whose sum is σ = 6506607662. Its totient is φ = 6506607660.

The previous prime is 6506607647. The next prime is 6506607671. The reversal of 6506607661 is 1667066056.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3930537636 + 2576070025 = 62694^2 + 50755^2 .

It is a cyclic number.

It is not a de Polignac number, because 6506607661 - 2¹³ = 6506599469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6506607671) 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, 3253303830 + 3253303831.

It is an arithmetic number, because the mean of its divisors is an integer number (3253303831).

Almost surely, 2^6506607661 is an apocalyptic number.

It is an amenable number.

6506607661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6506607661 is an equidigital number, since it uses as much as digits as its factorization.

6506607661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 6506607661 is about 80663.5460477656. The cubic root of 6506607661 is about 1866.8877531752.

The spelling of 6506607661 in words is "six billion, five hundred six million, six hundred seven thousand, six hundred sixty-one".