663871 has 8 divisors (see below), whose sum is σ = 721280. Its totient is φ = 607392.

The previous prime is 663869. The next prime is 663881. The reversal of 663871 is 178366.

663871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 663871 - 2¹ = 663869 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 (663821) 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, 2785 + ... + 3013.

It is an arithmetic number, because the mean of its divisors is an integer number (90160).

2⁶⁶³⁸⁷¹ is an apocalyptic number.

663871 is a deficient number, since it is larger than the sum of its proper divisors (57409).

663871 is a wasteful number, since it uses less digits than its factorization.

663871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465.

The product of its digits is 6048, while the sum is 31.

The square root of 663871 is about 814.7827931418. The cubic root of 663871 is about 87.2357633933.

The spelling of 663871 in words is "six hundred sixty-three thousand, eight hundred seventy-one".