669994 has 16 divisors (see below), whose sum is σ = 1100232. Its totient is φ = 304128.

The previous prime is 669989. The next prime is 670001. The reversal of 669994 is 499966.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 455625 + 214369 = 675^2 + 463^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 669994.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1722 + ... + 2074.

2⁶⁶⁹⁹⁹⁴ is an apocalyptic number.

669994 is a deficient number, since it is larger than the sum of its proper divisors (430238).

669994 is a wasteful number, since it uses less digits than its factorization.

669994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441.

The product of its digits is 104976, while the sum is 43.

The square root of 669994 is about 818.5316120957. The cubic root of 669994 is about 87.5031400234.

The spelling of 669994 in words is "six hundred sixty-nine thousand, nine hundred ninety-four".