840680641 has 2 divisors, whose sum is σ = 840680642. Its totient is φ = 840680640.

The previous prime is 840680639. The next prime is 840680693. The reversal of 840680641 is 146086048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 713103616 + 127577025 = 26704^2 + 11295^2 .

It is a cyclic number.

It is not a de Polignac number, because 840680641 - 2¹ = 840680639 is a prime.

Together with 840680639, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 840680641.

It is not a weakly prime, because it can be changed into another prime (840680941) 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, 420340320 + 420340321.

It is an arithmetic number, because the mean of its divisors is an integer number (420340321).

Almost surely, 2^840680641 is an apocalyptic number.

It is an amenable number.

840680641 is a deficient number, since it is larger than the sum of its proper divisors (1).

840680641 is an equidigital number, since it uses as much as digits as its factorization.

840680641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 840680641 is about 28994.4932875193. The cubic root of 840680641 is about 943.7935729718.

The spelling of 840680641 in words is "eight hundred forty million, six hundred eighty thousand, six hundred forty-one".