816563 has 8 divisors (see below), whose sum is σ = 937920. Its totient is φ = 703080.

The previous prime is 816559. The next prime is 816581. The reversal of 816563 is 365618.

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 816563 - 2² = 816559 is a prime.

It is a super-3 number, since 3×816563³ = 1633391708707696641, which contains 333 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a plaindrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 816563.

It is not an unprimeable number, because it can be changed into a prime (816593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1745 + ... + 2162.

It is an arithmetic number, because the mean of its divisors is an integer number (117240).

2⁸¹⁶⁵⁶³ is an apocalyptic number.

816563 is a deficient number, since it is larger than the sum of its proper divisors (121357).

816563 is a wasteful number, since it uses less digits than its factorization.

816563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3937.

The product of its digits is 4320, while the sum is 29.

The square root of 816563 is about 903.6387552557. The cubic root of 816563 is about 93.4680608116.

It can be divided in two parts, 8165 and 63, that added together give a palindrome (8228).

The spelling of 816563 in words is "eight hundred sixteen thousand, five hundred sixty-three".