2561840386560 has 1280 divisors, whose sum is σ = 11368872345600. Its totient is φ = 532365115392.

The previous prime is 2561840386541. The next prime is 2561840386591. The reversal of 2561840386560 is 656830481652.

2561840386560 is a `hidden beast` number, since 2 + 5 + 6 + 1 + 8 + 40 + 38 + 6 + 560 = 666.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 2561840386497 and 2561840386506.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 421421601 + ... + 421427679.

It is an arithmetic number, because the mean of its divisors is an integer number (8881931520).

Almost surely, 2^{2561840386560} is an apocalyptic number.

2561840386560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2561840386560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5684436172800).

2561840386560 is an abundant number, since it is smaller than the sum of its proper divisors (8807031959040).

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

2561840386560 is a wasteful number, since it uses less digits than its factorization.

2561840386560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6198 (or 6176 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 54.

The spelling of 2561840386560 in words is "two trillion, five hundred sixty-one billion, eight hundred forty million, three hundred eighty-six thousand, five hundred sixty".