669939 has 4 divisors (see below), whose sum is σ = 893256. Its totient is φ = 446624.

The previous prime is 669937. The next prime is 669943. The reversal of 669939 is 939966.

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 669939 - 2¹ = 669937 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 669939.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669939.

It is not an unprimeable number, because it can be changed into a prime (669931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111654 + ... + 111659.

It is an arithmetic number, because the mean of its divisors is an integer number (223314).

2⁶⁶⁹⁹³⁹ is an apocalyptic number.

669939 is a deficient number, since it is larger than the sum of its proper divisors (223317).

669939 is a wasteful number, since it uses less digits than its factorization.

669939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223316.

The product of its digits is 78732, while the sum is 42.

The square root of 669939 is about 818.4980146586. The cubic root of 669939 is about 87.5007455719.

The spelling of 669939 in words is "six hundred sixty-nine thousand, nine hundred thirty-nine".