6687997847 has 2 divisors, whose sum is σ = 6687997848. Its totient is φ = 6687997846.

The previous prime is 6687997801. The next prime is 6687997909. The reversal of 6687997847 is 7487997866.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6687997847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6687990847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343998923 + 3343998924.

It is an arithmetic number, because the mean of its divisors is an integer number (3343998924).

Almost surely, 2^6687997847 is an apocalyptic number.

6687997847 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687997847 is an equidigital number, since it uses as much as digits as its factorization.

6687997847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256048128, while the sum is 71.

The square root of 6687997847 is about 81780.1800377084. The cubic root of 6687997847 is about 1884.0772615354.

The spelling of 6687997847 in words is "six billion, six hundred eighty-seven million, nine hundred ninety-seven thousand, eight hundred forty-seven".