6687816885 has 24 divisors (see below), whose sum is σ = 11874956184. Its totient is φ = 3479838720.

The previous prime is 6687816871. The next prime is 6687816887. The reversal of 6687816885 is 5886187866.

It can be written as a sum of positive squares in 4 ways, for example, as 2792241 + 6685024644 = 1671^2 + 81762^2 .

It is not a de Polignac number, because 6687816885 - 2⁵ = 6687816853 is a prime.

It is a super-2 number, since 2×6687816885² = 89453789374582206450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6687816887) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1810572 + ... + 1814261.

It is an arithmetic number, because the mean of its divisors is an integer number (494789841).

Almost surely, 2^6687816885 is an apocalyptic number.

It is an amenable number.

6687816885 is a deficient number, since it is larger than the sum of its proper divisors (5187139299).

6687816885 is a wasteful number, since it uses less digits than its factorization.

6687816885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3624885 (or 3624882 counting only the distinct ones).

The product of its digits is 30965760, while the sum is 63.

The square root of 6687816885 is about 81779.0736374532. The cubic root of 6687816885 is about 1884.0602684346.

The spelling of 6687816885 in words is "six billion, six hundred eighty-seven million, eight hundred sixteen thousand, eight hundred eighty-five".