6864661609 has 4 divisors (see below), whose sum is σ = 7392712516. Its totient is φ = 6336610704.

The previous prime is 6864661577. The next prime is 6864661619. The reversal of 6864661609 is 9061664686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9061664686 = 2 ⋅4530832343.

It can be written as a sum of positive squares in 2 ways, for example, as 4502410000 + 2362251609 = 67100^2 + 48603^2 .

It is a cyclic number.

It is not a de Polignac number, because 6864661609 - 2⁵ = 6864661577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6864661619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264025434 + ... + 264025459.

It is an arithmetic number, because the mean of its divisors is an integer number (1848178129).

Almost surely, 2^6864661609 is an apocalyptic number.

It is an amenable number.

6864661609 is a deficient number, since it is larger than the sum of its proper divisors (528050907).

6864661609 is a wasteful number, since it uses less digits than its factorization.

6864661609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528050906.

The product of its (nonzero) digits is 2239488, while the sum is 52.

The square root of 6864661609 is about 82853.2534605612. The cubic root of 6864661609 is about 1900.5226271435.

The spelling of 6864661609 in words is "six billion, eight hundred sixty-four million, six hundred sixty-one thousand, six hundred nine".