840728677 has 4 divisors (see below), whose sum is σ = 843720876. Its totient is φ = 837736480.

The previous prime is 840728671. The next prime is 840728717. The reversal of 840728677 is 776827048.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 321162241 + 519566436 = 17921^2 + 22794^2 .

It is a cyclic number.

It is not a de Polignac number, because 840728677 - 2¹¹ = 840726629 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 840728677.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840728671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1495678 + ... + 1496239.

It is an arithmetic number, because the mean of its divisors is an integer number (210930219).

Almost surely, 2^840728677 is an apocalyptic number.

It is an amenable number.

840728677 is a deficient number, since it is larger than the sum of its proper divisors (2992199).

840728677 is a wasteful number, since it uses less digits than its factorization.

840728677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992198.

The product of its (nonzero) digits is 1053696, while the sum is 49.

The square root of 840728677 is about 28995.3216398784. The cubic root of 840728677 is about 943.8115485669.

The spelling of 840728677 in words is "eight hundred forty million, seven hundred twenty-eight thousand, six hundred seventy-seven".