669551 has 2 divisors, whose sum is σ = 669552. Its totient is φ = 669550.

The previous prime is 669527. The next prime is 669577. The reversal of 669551 is 155966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 669551 - 2¹⁰ = 668527 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 669551.

It is not a weakly prime, because it can be changed into another prime (669451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334775 + 334776.

It is an arithmetic number, because the mean of its divisors is an integer number (334776).

2⁶⁶⁹⁵⁵¹ is an apocalyptic number.

669551 is a deficient number, since it is larger than the sum of its proper divisors (1).

669551 is an equidigital number, since it uses as much as digits as its factorization.

669551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8100, while the sum is 32.

The square root of 669551 is about 818.2609608187. The cubic root of 669551 is about 87.4838500806.

The spelling of 669551 in words is "six hundred sixty-nine thousand, five hundred fifty-one".