663766 has 4 divisors (see below), whose sum is σ = 995652. Its totient is φ = 331882.

The previous prime is 663763. The next prime is 663787. The reversal of 663766 is 667366.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165940 + ... + 165943.

It is an arithmetic number, because the mean of its divisors is an integer number (248913).

2⁶⁶³⁷⁶⁶ is an apocalyptic number.

663766 is a deficient number, since it is larger than the sum of its proper divisors (331886).

663766 is a wasteful number, since it uses less digits than its factorization.

663766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331885.

The product of its digits is 27216, while the sum is 34.

The square root of 663766 is about 814.7183562434. The cubic root of 663766 is about 87.2311639867.

Subtracting 663766 from its reverse (667366), we obtain a square (3600 = 60²).

The spelling of 663766 in words is "six hundred sixty-three thousand, seven hundred sixty-six".