263988 has 18 divisors (see below), whose sum is σ = 667394. Its totient is φ = 87984.

The previous prime is 263983. The next prime is 264007. The reversal of 263988 is 889362.

It can be written as a sum of positive squares in only one way, i.e., 142884 + 121104 = 378^2 + 348^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 7333 = 263988 / (2 + 6 + 3 + 9 + 8 + 8).

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (263983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3631 + ... + 3702.

2²⁶³⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

263988 is an abundant number, since it is smaller than the sum of its proper divisors (403406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

263988 is a wasteful number, since it uses less digits than its factorization.

263988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7343 (or 7338 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 263988 is about 513.7976255297. The cubic root of 263988 is about 64.1497146051.

It can be divided in two parts, 2639 and 88, that multiplied together give a palindrome (232232).

The spelling of 263988 in words is "two hundred sixty-three thousand, nine hundred eighty-eight".