663623 has 4 divisors (see below), whose sum is σ = 666360. Its totient is φ = 660888.

The previous prime is 663601. The next prime is 663631. The reversal of 663623 is 326366.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663623 is a prime.

It is a super-2 number, since 2×663623² = 880790972258, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 663592 and 663601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 965 + ... + 1502.

It is an arithmetic number, because the mean of its divisors is an integer number (166590).

2⁶⁶³⁶²³ is an apocalyptic number.

663623 is a deficient number, since it is larger than the sum of its proper divisors (2737).

663623 is a wasteful number, since it uses less digits than its factorization.

663623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2736.

The product of its digits is 3888, while the sum is 26.

The square root of 663623 is about 814.6305911270. The cubic root of 663623 is about 87.2248992526.

Adding to 663623 its reverse (326366), we get a palindrome (989989).

It can be divided in two parts, 6636 and 23, that multiplied together give a triangular number (152628 = T₅₅₂).

The spelling of 663623 in words is "six hundred sixty-three thousand, six hundred twenty-three".