669865 has 8 divisors (see below), whose sum is σ = 918720. Its totient is φ = 459312.

The previous prime is 669863. The next prime is 669869. The reversal of 669865 is 568966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 669865 - 2¹ = 669863 is a prime.

669865 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (669863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9535 + ... + 9604.

It is an arithmetic number, because the mean of its divisors is an integer number (114840).

2⁶⁶⁹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

669865 is a deficient number, since it is larger than the sum of its proper divisors (248855).

669865 is a wasteful number, since it uses less digits than its factorization.

669865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19151.

The product of its digits is 77760, while the sum is 40.

The square root of 669865 is about 818.4528086579. The cubic root of 669865 is about 87.4975237394.

The spelling of 669865 in words is "six hundred sixty-nine thousand, eight hundred sixty-five".