263999 has 8 divisors (see below), whose sum is σ = 278208. Its totient is φ = 250240.

The previous prime is 263983. The next prime is 264007. The reversal of 263999 is 999362.

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 263999 - 2⁴ = 263983 is a prime.

It is a Duffinian number.

263999 is a modest number, since divided by 999 gives 263 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (263909) 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, 1859 + ... + 1995.

It is an arithmetic number, because the mean of its divisors is an integer number (34776).

2²⁶³⁹⁹⁹ is an apocalyptic number.

263999 is a deficient number, since it is larger than the sum of its proper divisors (14209).

263999 is a wasteful number, since it uses less digits than its factorization.

263999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225.

The product of its digits is 26244, while the sum is 38.

The square root of 263999 is about 513.8083300220. The cubic root of 263999 is about 64.1506056015.

The spelling of 263999 in words is "two hundred sixty-three thousand, nine hundred ninety-nine".