669637 has 2 divisors, whose sum is σ = 669638. Its totient is φ = 669636.

The previous prime is 669611. The next prime is 669649. The reversal of 669637 is 736966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 349281 + 320356 = 591^2 + 566^2 .

It is a cyclic number.

It is not a de Polignac number, because 669637 - 2¹⁹ = 145349 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 669596 and 669605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334818 + 334819.

It is an arithmetic number, because the mean of its divisors is an integer number (334819).

2⁶⁶⁹⁶³⁷ is an apocalyptic number.

It is an amenable number.

669637 is a deficient number, since it is larger than the sum of its proper divisors (1).

669637 is an equidigital number, since it uses as much as digits as its factorization.

669637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 37.

The square root of 669637 is about 818.3135096037. The cubic root of 669637 is about 87.4875955205.

The spelling of 669637 in words is "six hundred sixty-nine thousand, six hundred thirty-seven".