669686 has 4 divisors (see below), whose sum is σ = 1004532.
Its totient is φ = 334842.
The previous prime is 669679. The next prime is 669689. The reversal of 669686 is 686966.
It is a semiprime because it is the product of two primes.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (669689) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167420 + ... + 167423.
It is an arithmetic number, because the mean of its divisors is an integer number (251133).
2669686 is an apocalyptic number.
669686 is a deficient number, since it is larger than the sum of its proper divisors (334846).
669686 is a wasteful number, since it uses less digits than its factorization.
669686 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 334845.
The product of its digits is 93312, while the sum is 41.
The square root of 669686 is about 818.3434486815.
The cubic root of 669686 is about 87.4897294067.
The spelling of 669686 in words is "six hundred sixty-nine thousand, six hundred eighty-six".