816663 has 16 divisors (see below), whose sum is σ = 1175040. Its totient is φ = 502656.

The previous prime is 816653. The next prime is 816667. The reversal of 816663 is 366618.

It is not a de Polignac number, because 816663 - 2¹⁷ = 685591 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 816663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816667) 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 15 ways as a sum of consecutive naturals, for example, 3298 + ... + 3536.

It is an arithmetic number, because the mean of its divisors is an integer number (73440).

2⁸¹⁶⁶⁶³ is an apocalyptic number.

816663 is a deficient number, since it is larger than the sum of its proper divisors (358377).

816663 is a wasteful number, since it uses less digits than its factorization.

816663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326.

The product of its digits is 5184, while the sum is 30.

The square root of 816663 is about 903.6940854072. The cubic root of 816663 is about 93.4718761631.

The spelling of 816663 in words is "eight hundred sixteen thousand, six hundred sixty-three".