666763 has 4 divisors (see below), whose sum is σ = 668680. Its totient is φ = 664848.

The previous prime is 666751. The next prime is 666769. The reversal of 666763 is 367666.

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-666763 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (666769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273 + ... + 1186.

It is an arithmetic number, because the mean of its divisors is an integer number (167170).

2⁶⁶⁶⁷⁶³ is an apocalyptic number.

666763 is a deficient number, since it is larger than the sum of its proper divisors (1917).

666763 is a wasteful number, since it uses less digits than its factorization.

666763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1916.

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

The square root of 666763 is about 816.5555706748. Note that the first 4 decimals coincide. The cubic root of 666763 is about 87.3622540169.

It can be divided in two parts, 66676 and 3, that multiplied together give a triangular number (200028 = T₆₃₂).

The spelling of 666763 in words is "six hundred sixty-six thousand, seven hundred sixty-three".