2561264681040 has 480 divisors, whose sum is σ = 9590221499040. Its totient is φ = 608244940800.

The previous prime is 2561264681039. The next prime is 2561264681071. The reversal of 2561264681040 is 401864621652.

It is a happy number.

2561264681040 is a `hidden beast` number, since 2 + 5 + 61 + 26 + 468 + 104 + 0 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 219226222656 + 2342038458384 = 468216^2 + 1530372^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 440001330 + ... + 440007150.

It is an arithmetic number, because the mean of its divisors is an integer number (19979628123).

Almost surely, 2^{2561264681040} is an apocalyptic number.

2561264681040 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 2561264681040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4795110749520).

2561264681040 is an abundant number, since it is smaller than the sum of its proper divisors (7028956818000).

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

2561264681040 is a wasteful number, since it uses less digits than its factorization.

2561264681040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7503 (or 7494 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 2561264681040 in words is "two trillion, five hundred sixty-one billion, two hundred sixty-four million, six hundred eighty-one thousand, forty".