669520 has 20 divisors (see below), whose sum is σ = 1556820. Its totient is φ = 267776.

The previous prime is 669481. The next prime is 669527. The reversal of 669520 is 25966.

669520 = T₅₁₅ + T₅₁₆ + ... + T₅₁₉.

It can be written as a sum of positive squares in 2 ways, for example, as 364816 + 304704 = 604^2 + 552^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669527) 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, 4105 + ... + 4264.

It is an arithmetic number, because the mean of its divisors is an integer number (77841).

2⁶⁶⁹⁵²⁰ is an apocalyptic number.

It is an amenable number.

669520 is an abundant number, since it is smaller than the sum of its proper divisors (887300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669520 is a wasteful number, since it uses less digits than its factorization.

669520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8382 (or 8376 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 669520 is about 818.2420179873. The cubic root of 669520 is about 87.4824999016.

The spelling of 669520 in words is "six hundred sixty-nine thousand, five hundred twenty".