663818 has 4 divisors (see below), whose sum is σ = 995730. Its totient is φ = 331908.

The previous prime is 663797. The next prime is 663821. The reversal of 663818 is 818366.

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

It can be written as a sum of positive squares in only one way, i.e., 628849 + 34969 = 793^2 + 187^2 .

It is a nialpdrome in base 7.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 663818.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165953 + ... + 165956.

2⁶⁶³⁸¹⁸ is an apocalyptic number.

663818 is a deficient number, since it is larger than the sum of its proper divisors (331912).

663818 is a wasteful number, since it uses less digits than its factorization.

663818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331911.

The product of its digits is 6912, while the sum is 32.

The square root of 663818 is about 814.7502684872. The cubic root of 663818 is about 87.2334418487.

The spelling of 663818 in words is "six hundred sixty-three thousand, eight hundred eighteen".