2688785221 has 2 divisors, whose sum is σ = 2688785222. Its totient is φ = 2688785220.

The previous prime is 2688785213. The next prime is 2688785237. The reversal of 2688785221 is 1225878862.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2368768900 + 320016321 = 48670^2 + 17889^2 .

It is a cyclic number.

It is not a de Polignac number, because 2688785221 - 2³ = 2688785213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2688785201) 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, 1344392610 + 1344392611.

It is an arithmetic number, because the mean of its divisors is an integer number (1344392611).

Almost surely, 2^2688785221 is an apocalyptic number.

It is an amenable number.

2688785221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2688785221 is an equidigital number, since it uses as much as digits as its factorization.

2688785221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 860160, while the sum is 49.

The square root of 2688785221 is about 51853.4976737346. The cubic root of 2688785221 is about 1390.5460341145.

The spelling of 2688785221 in words is "two billion, six hundred eighty-eight million, seven hundred eighty-five thousand, two hundred twenty-one".