669663 has 12 divisors (see below), whose sum is σ = 993928. Its totient is φ = 434160.

The previous prime is 669661. The next prime is 669667. The reversal of 669663 is 366966.

It is not a de Polignac number, because 669663 - 2¹ = 669661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 673 + ... + 1338.

2⁶⁶⁹⁶⁶³ is an apocalyptic number.

669663 is a deficient number, since it is larger than the sum of its proper divisors (324265).

669663 is a wasteful number, since it uses less digits than its factorization.

669663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2054 (or 2051 counting only the distinct ones).

The product of its digits is 34992, while the sum is 36.

The square root of 669663 is about 818.3293957814. The cubic root of 669663 is about 87.4887277996.

The spelling of 669663 in words is "six hundred sixty-nine thousand, six hundred sixty-three".