668888289 has 6 divisors (see below), whose sum is σ = 966171986. Its totient is φ = 445925520.

The previous prime is 668888287. The next prime is 668888317. The reversal of 668888289 is 982888866.

It can be written as a sum of positive squares in only one way, i.e., 605160000 + 63728289 = 24600^2 + 7983^2 .

It is not a de Polignac number, because 668888289 - 2¹ = 668888287 is a prime.

It is a super-2 number, since 2×668888289² = 894823086322695042, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668888281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37160452 + ... + 37160469.

Almost surely, 2^668888289 is an apocalyptic number.

It is an amenable number.

668888289 is a deficient number, since it is larger than the sum of its proper divisors (297283697).

668888289 is a wasteful number, since it uses less digits than its factorization.

668888289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74320927 (or 74320924 counting only the distinct ones).

The product of its digits is 21233664, while the sum is 63.

The square root of 668888289 is about 25862.8747242065. The cubic root of 668888289 is about 874.5497717505.

The spelling of 668888289 in words is "six hundred sixty-eight million, eight hundred eighty-eight thousand, two hundred eighty-nine".