6665655517 has 2 divisors, whose sum is σ = 6665655518. Its totient is φ = 6665655516.

The previous prime is 6665655497. The next prime is 6665655523. The reversal of 6665655517 is 7155565666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4182726276 + 2482929241 = 64674^2 + 49829^2 .

It is a cyclic number.

It is not a de Polignac number, because 6665655517 - 2¹⁵ = 6665622749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6665655547) 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, 3332827758 + 3332827759.

It is an arithmetic number, because the mean of its divisors is an integer number (3332827759).

Almost surely, 2^6665655517 is an apocalyptic number.

It is an amenable number.

6665655517 is a deficient number, since it is larger than the sum of its proper divisors (1).

6665655517 is an equidigital number, since it uses as much as digits as its factorization.

6665655517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5670000, while the sum is 52.

The square root of 6665655517 is about 81643.4658561235. The cubic root of 6665655517 is about 1881.9769001243.

The spelling of 6665655517 in words is "six billion, six hundred sixty-five million, six hundred fifty-five thousand, five hundred seventeen".