6645505687 has 2 divisors, whose sum is σ = 6645505688. Its totient is φ = 6645505686.

The previous prime is 6645505663. The next prime is 6645505709. The reversal of 6645505687 is 7865055466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6645505687 - 2¹¹ = 6645503639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6645575687) 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, 3322752843 + 3322752844.

It is an arithmetic number, because the mean of its divisors is an integer number (3322752844).

Almost surely, 2^6645505687 is an apocalyptic number.

6645505687 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645505687 is an equidigital number, since it uses as much as digits as its factorization.

6645505687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048000, while the sum is 52.

The square root of 6645505687 is about 81519.9710929782. The cubic root of 6645505687 is about 1880.0786226927.

The spelling of 6645505687 in words is "six billion, six hundred forty-five million, five hundred five thousand, six hundred eighty-seven".