6561684942 has 16 divisors (see below), whose sum is σ = 13575900240. Its totient is φ = 2111806592.

The previous prime is 6561684923. The next prime is 6561684953. The reversal of 6561684942 is 2494861656.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18855243 + ... + 18855590.

It is an arithmetic number, because the mean of its divisors is an integer number (848493765).

Almost surely, 2^6561684942 is an apocalyptic number.

6561684942 is an abundant number, since it is smaller than the sum of its proper divisors (7014215298).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561684942 is a wasteful number, since it uses less digits than its factorization.

6561684942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37710867.

The product of its digits is 2488320, while the sum is 51.

The square root of 6561684942 is about 81004.2279266953. The cubic root of 6561684942 is about 1872.1405841943.

The spelling of 6561684942 in words is "six billion, five hundred sixty-one million, six hundred eighty-four thousand, nine hundred forty-two".