840128837 has 2 divisors, whose sum is σ = 840128838. Its totient is φ = 840128836.

The previous prime is 840128819. The next prime is 840128851. The reversal of 840128837 is 738821048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674388961 + 165739876 = 25969^2 + 12874^2 .

It is a cyclic number.

It is not a de Polignac number, because 840128837 - 2¹⁴ = 840112453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 840128794 and 840128803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840128857) 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, 420064418 + 420064419.

It is an arithmetic number, because the mean of its divisors is an integer number (420064419).

Almost surely, 2^840128837 is an apocalyptic number.

It is an amenable number.

840128837 is a deficient number, since it is larger than the sum of its proper divisors (1).

840128837 is an equidigital number, since it uses as much as digits as its factorization.

840128837 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 41.

The square root of 840128837 is about 28984.9760565711. The cubic root of 840128837 is about 943.5870327670.

The spelling of 840128837 in words is "eight hundred forty million, one hundred twenty-eight thousand, eight hundred thirty-seven".