669967 has 4 divisors (see below), whose sum is σ = 699120. Its totient is φ = 640816.

The previous prime is 669947. The next prime is 669971. The reversal of 669967 is 769966.

It is a happy number.

669967 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 669967 - 2⁷ = 669839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669967.

It is not an unprimeable number, because it can be changed into a prime (669937) 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, 14542 + ... + 14587.

It is an arithmetic number, because the mean of its divisors is an integer number (174780).

2⁶⁶⁹⁹⁶⁷ is an apocalyptic number.

669967 is a deficient number, since it is larger than the sum of its proper divisors (29153).

669967 is a wasteful number, since it uses less digits than its factorization.

669967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29152.

The product of its digits is 122472, while the sum is 43.

The square root of 669967 is about 818.5151189807. The cubic root of 669967 is about 87.5019645817.

Subtracting 669967 from its reverse (769966), we obtain a palindrome (99999).

The spelling of 669967 in words is "six hundred sixty-nine thousand, nine hundred sixty-seven".