816556 has 24 divisors (see below), whose sum is σ = 1580544. Its totient is φ = 366720.

The previous prime is 816547. The next prime is 816559. The reversal of 816556 is 655618.

It is a super-3 number, since 3×816556³ = 1633349702234422848, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (816559) 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 7 ways as a sum of consecutive naturals, for example, 1941 + ... + 2323.

It is an arithmetic number, because the mean of its divisors is an integer number (65856).

2⁸¹⁶⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

816556 is a deficient number, since it is larger than the sum of its proper divisors (763988).

816556 is a wasteful number, since it uses less digits than its factorization.

816556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 439 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

The square root of 816556 is about 903.6348820182. The cubic root of 816556 is about 93.4677937254.

The spelling of 816556 in words is "eight hundred sixteen thousand, five hundred fifty-six".