263978 has 24 divisors (see below), whose sum is σ = 474336. Its totient is φ = 109200.

The previous prime is 263957. The next prime is 263983. The reversal of 263978 is 879362.

It is a super-3 number, since 3×263978³ = 55185433341952056, which contains 333 as substring.

It is a nialpdrome in base 13.

It is an unprimeable number.

263978 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 11 ways as a sum of consecutive naturals, for example, 3683 + ... + 3753.

It is an arithmetic number, because the mean of its divisors is an integer number (19764).

2²⁶³⁹⁷⁸ is an apocalyptic number.

263978 is a deficient number, since it is larger than the sum of its proper divisors (210358).

263978 is a wasteful number, since it uses less digits than its factorization.

263978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 97 counting only the distinct ones).

The product of its digits is 18144, while the sum is 35.

The square root of 263978 is about 513.7878939796. The cubic root of 263978 is about 64.1489045869.

It can be divided in two parts, 26 and 3978, that added together give a palindrome (4004).

The spelling of 263978 in words is "two hundred sixty-three thousand, nine hundred seventy-eight".