668888893 has 4 divisors (see below), whose sum is σ = 668948220. Its totient is φ = 668829568.

The previous prime is 668888887. The next prime is 668888903. The reversal of 668888893 is 398888866.

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 can be written as a sum of positive squares in 2 ways, for example, as 147816964 + 521071929 = 12158^2 + 22827^2 .

It is a cyclic number.

It is not a de Polignac number, because 668888893 - 2⁵ = 668888861 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 (668888833) 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, 6958 + ... + 37231.

It is an arithmetic number, because the mean of its divisors is an integer number (167237055).

Almost surely, 2^668888893 is an apocalyptic number.

It is an amenable number.

668888893 is a deficient number, since it is larger than the sum of its proper divisors (59327).

668888893 is a wasteful number, since it uses less digits than its factorization.

668888893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59326.

The product of its digits is 31850496, while the sum is 64.

The square root of 668888893 is about 25862.8864011734. The cubic root of 668888893 is about 874.5500349872.

The spelling of 668888893 in words is "six hundred sixty-eight million, eight hundred eighty-eight thousand, eight hundred ninety-three".