663501 has 8 divisors (see below), whose sum is σ = 898144. Its totient is φ = 435600.

The previous prime is 663463. The next prime is 663517. The reversal of 663501 is 105366.

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

It is not a de Polignac number, because 663501 - 2⁶ = 663437 is a prime.

It is a Duffinian number.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1450 + ... + 1851.

It is an arithmetic number, because the mean of its divisors is an integer number (112268).

2⁶⁶³⁵⁰¹ is an apocalyptic number.

It is an amenable number.

663501 is a deficient number, since it is larger than the sum of its proper divisors (234643).

663501 is a wasteful number, since it uses less digits than its factorization.

663501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3371.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 663501 is about 814.5557071189. Note that the first 3 decimals coincide. The cubic root of 663501 is about 87.2195538031.

Adding to 663501 its reverse (105366), we get a palindrome (768867).

The spelling of 663501 in words is "six hundred sixty-three thousand, five hundred one".