667888889 has 4 divisors (see below), whose sum is σ = 674016420. Its totient is φ = 661761360.

The previous prime is 667888883. The next prime is 667888901. The reversal of 667888889 is 988888766.

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

It can be written as a sum of positive squares in 2 ways, for example, as 496933264 + 170955625 = 22292^2 + 13075^2 .

It is a cyclic number.

It is not a de Polignac number, because 667888889 - 2¹⁶ = 667823353 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (667888883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3063602 + ... + 3063819.

It is an arithmetic number, because the mean of its divisors is an integer number (168504105).

Almost surely, 2^667888889 is an apocalyptic number.

It is an amenable number.

667888889 is a deficient number, since it is larger than the sum of its proper divisors (6127531).

667888889 is a wasteful number, since it uses less digits than its factorization.

667888889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6127530.

The product of its digits is 74317824, while the sum is 68.

The square root of 667888889 is about 25843.5463704191. The cubic root of 667888889 is about 874.1139936005.

The spelling of 667888889 in words is "six hundred sixty-seven million, eight hundred eighty-eight thousand, eight hundred eighty-nine".