663545 has 4 divisors (see below), whose sum is σ = 796260. Its totient is φ = 530832.

The previous prime is 663541. The next prime is 663547. The reversal of 663545 is 545366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 545366 = 2 ⋅272683.

It can be written as a sum of positive squares in 2 ways, for example, as 379456 + 284089 = 616^2 + 533^2 .

It is a cyclic number.

It is not a de Polignac number, because 663545 - 2² = 663541 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (663541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66350 + ... + 66359.

It is an arithmetic number, because the mean of its divisors is an integer number (199065).

2⁶⁶³⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

663545 is a deficient number, since it is larger than the sum of its proper divisors (132715).

663545 is a wasteful number, since it uses less digits than its factorization.

663545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132714.

The product of its digits is 10800, while the sum is 29.

The square root of 663545 is about 814.5827152598. The cubic root of 663545 is about 87.2214817457.

The spelling of 663545 in words is "six hundred sixty-three thousand, five hundred forty-five".