2108826781 has 2 divisors, whose sum is σ = 2108826782. Its totient is φ = 2108826780.

The previous prime is 2108826757. The next prime is 2108826817. The reversal of 2108826781 is 1876288012.

Together with next prime (2108826817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1469495556 + 639331225 = 38334^2 + 25285^2 .

It is a cyclic number.

It is not a de Polignac number, because 2108826781 - 2⁵ = 2108826749 is a prime.

It is a super-2 number, since 2×2108826781² = 8894300784525643922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2108826721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1054413390 + 1054413391.

It is an arithmetic number, because the mean of its divisors is an integer number (1054413391).

Almost surely, 2^2108826781 is an apocalyptic number.

It is an amenable number.

2108826781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2108826781 is an equidigital number, since it uses as much as digits as its factorization.

2108826781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 2108826781 is about 45921.9640368310. The cubic root of 2108826781 is about 1282.3708462265.

The spelling of 2108826781 in words is "two billion, one hundred eight million, eight hundred twenty-six thousand, seven hundred eighty-one".