2685619681 has 2 divisors, whose sum is σ = 2685619682. Its totient is φ = 2685619680.

The previous prime is 2685619661. The next prime is 2685619709. The reversal of 2685619681 is 1869165862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2588774400 + 96845281 = 50880^2 + 9841^2 .

It is a cyclic number.

It is not a de Polignac number, because 2685619681 - 2⁹ = 2685619169 is a prime.

It is a super-2 number, since 2×2685619681² = 14425106141949083522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2685619661) by changing a digit.

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 as a sum of consecutive naturals, namely, 1342809840 + 1342809841.

It is an arithmetic number, because the mean of its divisors is an integer number (1342809841).

Almost surely, 2^2685619681 is an apocalyptic number.

It is an amenable number.

2685619681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2685619681 is an equidigital number, since it uses as much as digits as its factorization.

2685619681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1244160, while the sum is 52.

The square root of 2685619681 is about 51822.9648032607. The cubic root of 2685619681 is about 1390.0001174887. Note that the first 3 decimals are identical.

The spelling of 2685619681 in words is "two billion, six hundred eighty-five million, six hundred nineteen thousand, six hundred eighty-one".