669279 has 12 divisors (see below), whose sum is σ = 968408. Its totient is φ = 408720.

The previous prime is 669271. The next prime is 669283. The reversal of 669279 is 972966.

It is not a de Polignac number, because 669279 - 2³ = 669271 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

669279 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5044 + ... + 5174.

2⁶⁶⁹²⁷⁹ is an apocalyptic number.

669279 is a deficient number, since it is larger than the sum of its proper divisors (299129).

669279 is a wasteful number, since it uses less digits than its factorization.

669279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 147 counting only the distinct ones).

The product of its digits is 40824, while the sum is 39.

The square root of 669279 is about 818.0947377902. The cubic root of 669279 is about 87.4720019265.

Multiplying 669279 by its sum of digits (39), we get a square (26101881 = 5109²).

669279 divided by its sum of digits (39) gives a square (17161 = 131²).

The spelling of 669279 in words is "six hundred sixty-nine thousand, two hundred seventy-nine".