669291 has 24 divisors (see below), whose sum is σ = 1080720. Its totient is φ = 366912.

The previous prime is 669289. The next prime is 669301. The reversal of 669291 is 192966.

It is a happy number.

It is not a de Polignac number, because 669291 - 2¹ = 669289 is a prime.

669291 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (669241) 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 23 ways as a sum of consecutive naturals, for example, 4185 + ... + 4341.

It is an arithmetic number, because the mean of its divisors is an integer number (45030).

2⁶⁶⁹²⁹¹ is an apocalyptic number.

669291 is a deficient number, since it is larger than the sum of its proper divisors (411429).

669291 is a wasteful number, since it uses less digits than its factorization.

669291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 196 counting only the distinct ones).

The product of its digits is 5832, while the sum is 33.

The square root of 669291 is about 818.1020718712. The cubic root of 669291 is about 87.4725247069.

The spelling of 669291 in words is "six hundred sixty-nine thousand, two hundred ninety-one".