669439 has 4 divisors (see below), whose sum is σ = 672480. Its totient is φ = 666400.

The previous prime is 669437. The next prime is 669451. The reversal of 669439 is 934966.

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 669439 - 2¹ = 669437 is a prime.

It is an Ulam number.

It is a Duffinian number.

669439 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 669398 and 669407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1162 + ... + 1639.

It is an arithmetic number, because the mean of its divisors is an integer number (168120).

2⁶⁶⁹⁴³⁹ is an apocalyptic number.

669439 is a deficient number, since it is larger than the sum of its proper divisors (3041).

669439 is a wasteful number, since it uses less digits than its factorization.

669439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3040.

The product of its digits is 34992, while the sum is 37.

The square root of 669439 is about 818.1925201320. The cubic root of 669439 is about 87.4789718176.

The spelling of 669439 in words is "six hundred sixty-nine thousand, four hundred thirty-nine".