667889 has 4 divisors (see below), whose sum is σ = 678900. Its totient is φ = 656880.

The previous prime is 667883. The next prime is 667903. The reversal of 667889 is 988766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988766 = 2 ⋅494383.

It can be written as a sum of positive squares in 2 ways, for example, as 27889 + 640000 = 167^2 + 800^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667889 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 (667883) 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, 5414 + ... + 5535.

It is an arithmetic number, because the mean of its divisors is an integer number (169725).

2⁶⁶⁷⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

667889 is a deficient number, since it is larger than the sum of its proper divisors (11011).

667889 is a wasteful number, since it uses less digits than its factorization.

667889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11010.

The product of its digits is 145152, while the sum is 44.

The square root of 667889 is about 817.2447613781. The cubic root of 667889 is about 87.4114042025.

The spelling of 667889 in words is "six hundred sixty-seven thousand, eight hundred eighty-nine".