6649410661 has 2 divisors, whose sum is σ = 6649410662. Its totient is φ = 6649410660.

The previous prime is 6649410643. The next prime is 6649410671. The reversal of 6649410661 is 1660149466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6647956225 + 1454436 = 81535^2 + 1206^2 .

It is a cyclic number.

It is not a de Polignac number, because 6649410661 - 2⁹ = 6649410149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6649410611) 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, 3324705330 + 3324705331.

It is an arithmetic number, because the mean of its divisors is an integer number (3324705331).

Almost surely, 2^6649410661 is an apocalyptic number.

It is an amenable number.

6649410661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6649410661 is an equidigital number, since it uses as much as digits as its factorization.

6649410661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 6649410661 is about 81543.9186021864. The cubic root of 6649410661 is about 1880.4468023789.

The spelling of 6649410661 in words is "six billion, six hundred forty-nine million, four hundred ten thousand, six hundred sixty-one".