6691487947 has 2 divisors, whose sum is σ = 6691487948. Its totient is φ = 6691487946.

The previous prime is 6691487923. The next prime is 6691487983. The reversal of 6691487947 is 7497841966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6691487947 - 2¹⁹ = 6690963659 is a prime.

It is not a weakly prime, because it can be changed into another prime (6691487447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3345743973 + 3345743974.

It is an arithmetic number, because the mean of its divisors is an integer number (3345743974).

Almost surely, 2^6691487947 is an apocalyptic number.

6691487947 is a deficient number, since it is larger than the sum of its proper divisors (1).

6691487947 is an equidigital number, since it uses as much as digits as its factorization.

6691487947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18289152, while the sum is 61.

The square root of 6691487947 is about 81801.5155544199. The cubic root of 6691487947 is about 1884.4049368085.

The spelling of 6691487947 in words is "six billion, six hundred ninety-one million, four hundred eighty-seven thousand, nine hundred forty-seven".