663844 has 6 divisors (see below), whose sum is σ = 1161734. Its totient is φ = 331920.

The previous prime is 663827. The next prime is 663853. The reversal of 663844 is 448366.

It can be written as a sum of positive squares in only one way, i.e., 656100 + 7744 = 810^2 + 88^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82977 + ... + 82984.

2⁶⁶³⁸⁴⁴ is an apocalyptic number.

It is an amenable number.

663844 is a deficient number, since it is larger than the sum of its proper divisors (497890).

663844 is a wasteful number, since it uses less digits than its factorization.

663844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165965 (or 165963 counting only the distinct ones).

The product of its digits is 13824, while the sum is 31.

The square root of 663844 is about 814.7662241404. The cubic root of 663844 is about 87.2345807351.

The spelling of 663844 in words is "six hundred sixty-three thousand, eight hundred forty-four".