2688643885 has 4 divisors (see below), whose sum is σ = 3226372668. Its totient is φ = 2150915104.

The previous prime is 2688643847. The next prime is 2688643897. The reversal of 2688643885 is 5883468862.

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

It can be written as a sum of positive squares in 2 ways, for example, as 842566729 + 1846077156 = 29027^2 + 42966^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2688643885 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268864384 + ... + 268864393.

It is an arithmetic number, because the mean of its divisors is an integer number (806593167).

Almost surely, 2^2688643885 is an apocalyptic number.

It is an amenable number.

2688643885 is a deficient number, since it is larger than the sum of its proper divisors (537728783).

2688643885 is an equidigital number, since it uses as much as digits as its factorization.

2688643885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537728782.

The product of its digits is 17694720, while the sum is 58.

The square root of 2688643885 is about 51852.1348162253. The cubic root of 2688643885 is about 1390.5216690027.

The spelling of 2688643885 in words is "two billion, six hundred eighty-eight million, six hundred forty-three thousand, eight hundred eighty-five".