666656063 has 4 divisors (see below), whose sum is σ = 666724440. Its totient is φ = 666587688.

The previous prime is 666656057. The next prime is 666656113. The reversal of 666656063 is 360656666.

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 666656063 - 2⁸ = 666655807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666656663) 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, 16520 + ... + 40077.

It is an arithmetic number, because the mean of its divisors is an integer number (166681110).

Almost surely, 2^666656063 is an apocalyptic number.

666656063 is a deficient number, since it is larger than the sum of its proper divisors (68377).

666656063 is a wasteful number, since it uses less digits than its factorization.

666656063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68376.

The product of its (nonzero) digits is 699840, while the sum is 44.

The square root of 666656063 is about 25819.6836347776. The cubic root of 666656063 is about 873.5758331337.

The spelling of 666656063 in words is "six hundred sixty-six million, six hundred fifty-six thousand, sixty-three".