663867 has 12 divisors (see below), whose sum is σ = 1015560. Its totient is φ = 416448.

The previous prime is 663857. The next prime is 663869. The reversal of 663867 is 768366.

It is a happy number.

It is not a de Polignac number, because 663867 - 2¹⁰ = 662843 is a prime.

663867 is a lucky number.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (663869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2017 + ... + 2322.

It is an arithmetic number, because the mean of its divisors is an integer number (84630).

2⁶⁶³⁸⁶⁷ is an apocalyptic number.

663867 is a deficient number, since it is larger than the sum of its proper divisors (351693).

663867 is a wasteful number, since it uses less digits than its factorization.

663867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4362 (or 4359 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 663867 is about 814.7803384962. The cubic root of 663867 is about 87.2355881867.

The spelling of 663867 in words is "six hundred sixty-three thousand, eight hundred sixty-seven".