668505563 has 16 divisors (see below), whose sum is σ = 748573056. Its totient is φ = 591743040.

The previous prime is 668505559. The next prime is 668505571. The reversal of 668505563 is 365505866.

It is a cyclic number.

It is not a de Polignac number, because 668505563 - 2² = 668505559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668505503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 162095 + ... + 166167.

It is an arithmetic number, because the mean of its divisors is an integer number (46785816).

Almost surely, 2^668505563 is an apocalyptic number.

668505563 is a deficient number, since it is larger than the sum of its proper divisors (80067493).

668505563 is a wasteful number, since it uses less digits than its factorization.

668505563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4474.

The product of its (nonzero) digits is 648000, while the sum is 44.

The square root of 668505563 is about 25855.4745266839. The cubic root of 668505563 is about 874.3829393109.

The spelling of 668505563 in words is "six hundred sixty-eight million, five hundred five thousand, five hundred sixty-three".