663669 has 12 divisors (see below), whose sum is σ = 985036. Its totient is φ = 430272.

The previous prime is 663661. The next prime is 663683. The reversal of 663669 is 966366.

It can be written as a sum of positive squares in 2 ways, for example, as 544644 + 119025 = 738^2 + 345^2 .

It is not a de Polignac number, because 663669 - 2³ = 663661 is a prime.

It is a super-2 number, since 2×663669² = 880913083122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663661) 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, 664 + ... + 1329.

2⁶⁶³⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

663669 is a deficient number, since it is larger than the sum of its proper divisors (321367).

663669 is a wasteful number, since it uses less digits than its factorization.

663669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2036 (or 2033 counting only the distinct ones).

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

The square root of 663669 is about 814.6588242939. The cubic root of 663669 is about 87.2269145800.

The spelling of 663669 in words is "six hundred sixty-three thousand, six hundred sixty-nine".