669629 has 4 divisors (see below), whose sum is σ = 678876. Its totient is φ = 660384.

The previous prime is 669611. The next prime is 669637. The reversal of 669629 is 926966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 926966 = 2 ⋅463483.

It can be written as a sum of positive squares in 2 ways, for example, as 158404 + 511225 = 398^2 + 715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-669629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 669592 and 669601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669649) 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 in 3 ways as a sum of consecutive naturals, for example, 4514 + ... + 4659.

It is an arithmetic number, because the mean of its divisors is an integer number (169719).

2⁶⁶⁹⁶²⁹ is an apocalyptic number.

It is an amenable number.

669629 is a deficient number, since it is larger than the sum of its proper divisors (9247).

669629 is an equidigital number, since it uses as much as digits as its factorization.

669629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9246.

The product of its digits is 34992, while the sum is 38.

The square root of 669629 is about 818.3086214870. The cubic root of 669629 is about 87.4872471210.

The spelling of 669629 in words is "six hundred sixty-nine thousand, six hundred twenty-nine".