668444866 has 16 divisors (see below), whose sum is σ = 1029775680. Its totient is φ = 325298800.

The previous prime is 668444831. The next prime is 668444873.

It is a happy number.

668444866 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16126 + ... + 39961.

It is an arithmetic number, because the mean of its divisors is an integer number (64360980).

Almost surely, 2^668444866 is an apocalyptic number.

668444866 is a deficient number, since it is larger than the sum of its proper divisors (361330814).

668444866 is a wasteful number, since it uses less digits than its factorization.

668444866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56249.

The product of its digits is 5308416, while the sum is 52.

The square root of 668444866 is about 25854.3007254112. The cubic root of 668444866 is about 874.3564752940.

The spelling of 668444866 in words is "six hundred sixty-eight million, four hundred forty-four thousand, eight hundred sixty-six".