663745 has 4 divisors (see below), whose sum is σ = 796500. Its totient is φ = 530992.

The previous prime is 663737. The next prime is 663763. The reversal of 663745 is 547366.

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 394384 + 269361 = 628^2 + 519^2 .

It is a cyclic number.

It is not a de Polignac number, because 663745 - 2³ = 663737 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66370 + ... + 66379.

It is an arithmetic number, because the mean of its divisors is an integer number (199125).

2⁶⁶³⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

663745 is a deficient number, since it is larger than the sum of its proper divisors (132755).

663745 is a wasteful number, since it uses less digits than its factorization.

663745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132754.

The product of its digits is 15120, while the sum is 31.

The square root of 663745 is about 814.7054682522. The cubic root of 663745 is about 87.2302440471.

The spelling of 663745 in words is "six hundred sixty-three thousand, seven hundred forty-five".