669744 has 30 divisors (see below), whose sum is σ = 1874756. Its totient is φ = 223200.

The previous prime is 669733. The next prime is 669763. The reversal of 669744 is 447966.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 669699 and 669708.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669744.

It is an unprimeable number.

669744 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2182 + ... + 2469.

2⁶⁶⁹⁷⁴⁴ is an apocalyptic number.

It is an amenable number.

669744 is an abundant number, since it is smaller than the sum of its proper divisors (1205012).

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

669744 is a wasteful number, since it uses less digits than its factorization.

669744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4665 (or 4656 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 669744 is about 818.3788853581. The cubic root of 669744 is about 87.4922550968.

The spelling of 669744 in words is "six hundred sixty-nine thousand, seven hundred forty-four".