840556 has 6 divisors (see below), whose sum is σ = 1470980. Its totient is φ = 420276.

The previous prime is 840547. The next prime is 840557. The reversal of 840556 is 655048.

It is not an unprimeable number, because it can be changed into a prime (840557) 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 as a sum of consecutive naturals, namely, 105066 + ... + 105073.

2⁸⁴⁰⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

840556 is a deficient number, since it is larger than the sum of its proper divisors (630424).

840556 is a wasteful number, since it uses less digits than its factorization.

840556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210143 (or 210141 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 840556 is about 916.8184116825. The cubic root of 840556 is about 94.3746927756.

The spelling of 840556 in words is "eight hundred forty thousand, five hundred fifty-six".