669591 has 24 divisors (see below), whose sum is σ = 1070160. Its totient is φ = 400896.

The previous prime is 669577. The next prime is 669607. The reversal of 669591 is 195966.

669591 is a `hidden beast` number, since 6 + 69 + 591 = 666.

It is not a de Polignac number, because 669591 - 2⁶ = 669527 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669591.

It is not an unprimeable number, because it can be changed into a prime (669551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6855 + ... + 6951.

It is an arithmetic number, because the mean of its divisors is an integer number (44590).

2⁶⁶⁹⁵⁹¹ is an apocalyptic number.

669591 is a deficient number, since it is larger than the sum of its proper divisors (400569).

669591 is a wasteful number, since it uses less digits than its factorization.

669591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 172 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 669591 is about 818.2854025339. The cubic root of 669591 is about 87.4855921856.

It can be divided in two parts, 6695 and 91, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 669591 in words is "six hundred sixty-nine thousand, five hundred ninety-one".