263440 has 40 divisors (see below), whose sum is σ = 636120. Its totient is φ = 101376.

The previous prime is 263437. The next prime is 263443. The reversal of 263440 is 44362.

It is an interprime number because it is at equal distance from previous prime (263437) and next prime (263443).

It can be written as a sum of positive squares in 4 ways, for example, as 36864 + 226576 = 192^2 + 476^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (263443) 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, 2916 + ... + 3004.

It is an arithmetic number, because the mean of its divisors is an integer number (15903).

263440 is a Friedman number, since it can be written as 6^4+4^3^(2+0), using all its digits and the basic arithmetic operations.

2²⁶³⁴⁴⁰ is an apocalyptic number.

263440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 263440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318060).

263440 is an abundant number, since it is smaller than the sum of its proper divisors (372680).

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

263440 is a wasteful number, since it uses less digits than its factorization.

263440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 263440 is about 513.2640645905. The cubic root of 263440 is about 64.1052954187.

It can be divided in two parts, 263 and 440, that added together give a triangular number (703 = T₃₇).

The spelling of 263440 in words is "two hundred sixty-three thousand, four hundred forty".