840678605 has 8 divisors (see below), whose sum is σ = 1086415512. Its totient is φ = 620808768.

The previous prime is 840678583. The next prime is 840678647. The reversal of 840678605 is 506876048.

It can be written as a sum of positive squares in 4 ways, for example, as 127735204 + 712943401 = 11302^2 + 26701^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 840678605 - 2¹⁶ = 840613069 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6466694 + ... + 6466823.

It is an arithmetic number, because the mean of its divisors is an integer number (135801939).

Almost surely, 2^840678605 is an apocalyptic number.

It is an amenable number.

840678605 is a deficient number, since it is larger than the sum of its proper divisors (245736907).

840678605 is a wasteful number, since it uses less digits than its factorization.

840678605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12933535.

The product of its (nonzero) digits is 322560, while the sum is 44.

The square root of 840678605 is about 28994.4581773828. The cubic root of 840678605 is about 943.7928110632.

The spelling of 840678605 in words is "eight hundred forty million, six hundred seventy-eight thousand, six hundred five".