669539 has 4 divisors (see below), whose sum is σ = 721056. Its totient is φ = 618024.

The previous prime is 669527. The next prime is 669551. The reversal of 669539 is 935966.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (669527) and next prime (669551).

It is a cyclic number.

It is not a de Polignac number, because 669539 - 2⁸ = 669283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669839) 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 3 ways as a sum of consecutive naturals, for example, 25739 + ... + 25764.

It is an arithmetic number, because the mean of its divisors is an integer number (180264).

2⁶⁶⁹⁵³⁹ is an apocalyptic number.

669539 is a deficient number, since it is larger than the sum of its proper divisors (51517).

669539 is a wasteful number, since it uses less digits than its factorization.

669539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51516.

The product of its digits is 43740, while the sum is 38.

The square root of 669539 is about 818.2536281618. The cubic root of 669539 is about 87.4833274356.

The spelling of 669539 in words is "six hundred sixty-nine thousand, five hundred thirty-nine".