563681666 has 4 divisors (see below), whose sum is σ = 845522502. Its totient is φ = 281840832.

The previous prime is 563681639. The next prime is 563681687. The reversal of 563681666 is 666186365.

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

It can be written as a sum of positive squares in only one way, i.e., 563065441 + 616225 = 23729^2 + 785^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 563681666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140920415 + ... + 140920418.

Almost surely, 2^563681666 is an apocalyptic number.

563681666 is a deficient number, since it is larger than the sum of its proper divisors (281840836).

563681666 is a wasteful number, since it uses less digits than its factorization.

563681666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281840835.

The product of its digits is 933120, while the sum is 47.

The square root of 563681666 is about 23741.9810883591. The cubic root of 563681666 is about 826.0594486895.

The spelling of 563681666 in words is "five hundred sixty-three million, six hundred eighty-one thousand, six hundred sixty-six".