840728671 has 2 divisors, whose sum is σ = 840728672. Its totient is φ = 840728670.

The previous prime is 840728617. The next prime is 840728717. The reversal of 840728671 is 176827048.

Together with previous prime (840728617) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 840728671 - 2²³ = 832340063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840728071) 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, 420364335 + 420364336.

It is an arithmetic number, because the mean of its divisors is an integer number (420364336).

Almost surely, 2^840728671 is an apocalyptic number.

840728671 is a deficient number, since it is larger than the sum of its proper divisors (1).

840728671 is an equidigital number, since it uses as much as digits as its factorization.

840728671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 840728671 is about 28995.3215364134. The cubic root of 840728671 is about 943.8115463217.

The spelling of 840728671 in words is "eight hundred forty million, seven hundred twenty-eight thousand, six hundred seventy-one".