668818899 has 12 divisors (see below), whose sum is σ = 1104082096. Its totient is φ = 382182192.

The previous prime is 668818889. The next prime is 668818903. The reversal of 668818899 is 998818866.

It is not a de Polignac number, because 668818899 - 2¹¹ = 668816851 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 10616173 = 668818899 / (6 + 6 + 8 + 8 + 1 + 8 + 8 + 9 + 9).

668818899 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668818889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5308024 + ... + 5308149.

Almost surely, 2^668818899 is an apocalyptic number.

668818899 is a deficient number, since it is larger than the sum of its proper divisors (435263197).

668818899 is a wasteful number, since it uses less digits than its factorization.

668818899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10616186 (or 10616183 counting only the distinct ones).

The product of its digits is 11943936, while the sum is 63.

The square root of 668818899 is about 25861.5331912089. The cubic root of 668818899 is about 874.5195289789.

The spelling of 668818899 in words is "six hundred sixty-eight million, eight hundred eighteen thousand, eight hundred ninety-nine".