2561969808 has 30 divisors (see below), whose sum is σ = 7169957574. Its totient is φ = 853989888.

The previous prime is 2561969783. The next prime is 2561969827. The reversal of 2561969808 is 8089691652.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2433646224 + 128323584 = 49332^2 + 11328^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8895585 + ... + 8895872.

Almost surely, 2^2561969808 is an apocalyptic number.

It is an amenable number.

2561969808 is an abundant number, since it is smaller than the sum of its proper divisors (4607987766).

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

2561969808 is a wasteful number, since it uses less digits than its factorization.

2561969808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17791471 (or 17791462 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The square root of 2561969808 is about 50615.9046940781. The cubic root of 2561969808 is about 1368.3315345020.

The spelling of 2561969808 in words is "two billion, five hundred sixty-one million, nine hundred sixty-nine thousand, eight hundred eight".