6561491312376 has 192 divisors, whose sum is σ = 23859968670720. Its totient is φ = 1573184712960.

The previous prime is 6561491312357. The next prime is 6561491312423. The reversal of 6561491312376 is 6732131941656.

6561491312376 is a `hidden beast` number, since 6 + 5 + 61 + 491 + 3 + 1 + 23 + 76 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45448320 + ... + 45592463.

It is an arithmetic number, because the mean of its divisors is an integer number (124270670160).

Almost surely, 2^{6561491312376} is an apocalyptic number.

6561491312376 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

6561491312376 is an abundant number, since it is smaller than the sum of its proper divisors (17298477358344).

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

6561491312376 is a wasteful number, since it uses less digits than its factorization.

6561491312376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91040826 (or 91040819 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 54.

The spelling of 6561491312376 in words is "six trillion, five hundred sixty-one billion, four hundred ninety-one million, three hundred twelve thousand, three hundred seventy-six".