647887716667 has 4 divisors (see below), whose sum is σ = 654566971576. Its totient is φ = 641208461760.

The previous prime is 647887716583. The next prime is 647887716757. The reversal of 647887716667 is 766617788746.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647887716667 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 647887716667.

It is not an unprimeable number, because it can be changed into a prime (647887756667) 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 in 3 ways as a sum of consecutive naturals, for example, 3339627309 + ... + 3339627502.

It is an arithmetic number, because the mean of its divisors is an integer number (163641742894).

Almost surely, 2^647887716667 is an apocalyptic number.

647887716667 is a deficient number, since it is larger than the sum of its proper divisors (6679254909).

647887716667 is an equidigital number, since it uses as much as digits as its factorization.

647887716667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6679254908.

The product of its digits is 796594176, while the sum is 73.

The spelling of 647887716667 in words is "six hundred forty-seven billion, eight hundred eighty-seven million, seven hundred sixteen thousand, six hundred sixty-seven".