663706 has 8 divisors (see below), whose sum is σ = 1022580. Its totient is φ = 322848.

The previous prime is 663683. The next prime is 663709. The reversal of 663706 is 607366.

It can be written as a sum of positive squares in 2 ways, for example, as 625681 + 38025 = 791^2 + 195^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (663709) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4411 + ... + 4558.

2⁶⁶³⁷⁰⁶ is an apocalyptic number.

663706 is a deficient number, since it is larger than the sum of its proper divisors (358874).

663706 is a wasteful number, since it uses less digits than its factorization.

663706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9008.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 663706 is about 814.6815328704. The cubic root of 663706 is about 87.2285355365.

It can be divided in two parts, 663 and 706, that added together give a square (1369 = 37²).

The spelling of 663706 in words is "six hundred sixty-three thousand, seven hundred six".