840838261 has 2 divisors, whose sum is σ = 840838262. Its totient is φ = 840838260.

The previous prime is 840838247. The next prime is 840838321. The reversal of 840838261 is 162838048.

840838261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 576288036 + 264550225 = 24006^2 + 16265^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840838261 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840878261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420419130 + 420419131.

It is an arithmetic number, because the mean of its divisors is an integer number (420419131).

Almost surely, 2^840838261 is an apocalyptic number.

It is an amenable number.

840838261 is a deficient number, since it is larger than the sum of its proper divisors (1).

840838261 is an equidigital number, since it uses as much as digits as its factorization.

840838261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 73728, while the sum is 40.

The square root of 840838261 is about 28997.2112624645. The cubic root of 840838261 is about 943.8525535325.

The spelling of 840838261 in words is "eight hundred forty million, eight hundred thirty-eight thousand, two hundred sixty-one".