663785 has 4 divisors (see below), whose sum is σ = 796548. Its totient is φ = 531024.

The previous prime is 663763. The next prime is 663787. The reversal of 663785 is 587366.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 80089 + 583696 = 283^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 663785 - 2⁸ = 663529 is a prime.

It is a super-2 number, since 2×663785² = 881221052450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66374 + ... + 66383.

It is an arithmetic number, because the mean of its divisors is an integer number (199137).

2⁶⁶³⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

663785 is a deficient number, since it is larger than the sum of its proper divisors (132763).

663785 is a wasteful number, since it uses less digits than its factorization.

663785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132762.

The product of its digits is 30240, while the sum is 35.

The square root of 663785 is about 814.7300166313. The cubic root of 663785 is about 87.2319962962.

The spelling of 663785 in words is "six hundred sixty-three thousand, seven hundred eighty-five".