840689471 has 2 divisors, whose sum is σ = 840689472. Its totient is φ = 840689470.

The previous prime is 840689467. The next prime is 840689483. The reversal of 840689471 is 174986048.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 840689471 - 2² = 840689467 is a prime.

It is a super-3 number, since 3×840689471³ (a number of 28 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840689411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420344735 + 420344736.

It is an arithmetic number, because the mean of its divisors is an integer number (420344736).

Almost surely, 2^840689471 is an apocalyptic number.

840689471 is a deficient number, since it is larger than the sum of its proper divisors (1).

840689471 is an equidigital number, since it uses as much as digits as its factorization.

840689471 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 387072, while the sum is 47.

The square root of 840689471 is about 28994.6455574128. The cubic root of 840689471 is about 943.7968773054.

It can be divided in two parts, 84068 and 9471, that added together give a palindrome (93539).

The spelling of 840689471 in words is "eight hundred forty million, six hundred eighty-nine thousand, four hundred seventy-one".