6561844159 has 4 divisors (see below), whose sum is σ = 7066601416. Its totient is φ = 6057086904.

The previous prime is 6561844151. The next prime is 6561844169. The reversal of 6561844159 is 9514481656.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 6561844159 - 2³ = 6561844151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561844151) 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, 252378609 + ... + 252378634.

It is an arithmetic number, because the mean of its divisors is an integer number (1766650354).

Almost surely, 2^6561844159 is an apocalyptic number.

6561844159 is a deficient number, since it is larger than the sum of its proper divisors (504757257).

6561844159 is a wasteful number, since it uses less digits than its factorization.

6561844159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504757256.

The product of its digits is 1036800, while the sum is 49.

The square root of 6561844159 is about 81005.2106904241. The cubic root of 6561844159 is about 1872.1557263516.

The spelling of 6561844159 in words is "six billion, five hundred sixty-one million, eight hundred forty-four thousand, one hundred fifty-nine".