666651763 has 4 divisors (see below), whose sum is σ = 666723600. Its totient is φ = 666579928.

The previous prime is 666651751. The next prime is 666651823. The reversal of 666651763 is 367156666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 666651763 - 2¹⁷ = 666520691 is a prime.

It is a super-2 number, since 2×666651763² = 888849146222016338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660651763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19495 + ... + 41392.

It is an arithmetic number, because the mean of its divisors is an integer number (166680900).

Almost surely, 2^666651763 is an apocalyptic number.

666651763 is a deficient number, since it is larger than the sum of its proper divisors (71837).

666651763 is a wasteful number, since it uses less digits than its factorization.

666651763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71836.

The product of its digits is 816480, while the sum is 46.

The square root of 666651763 is about 25819.6003648391. The cubic root of 666651763 is about 873.5739549118.

The spelling of 666651763 in words is "six hundred sixty-six million, six hundred fifty-one thousand, seven hundred sixty-three".