249840 has 60 divisors (see below), whose sum is σ = 841464. Its totient is φ = 66432.

The previous prime is 249833. The next prime is 249853. The reversal of 249840 is 48942.

It is a tau number, because it is divible by the number of its divisors (60).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 547 + ... + 893.

2²⁴⁹⁸⁴⁰ is an apocalyptic number.

249840 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 249840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (420732).

249840 is an abundant number, since it is smaller than the sum of its proper divisors (591624).

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

249840 is a wasteful number, since it uses less digits than its factorization.

249840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 249840 is about 499.8399743918. The cubic root of 249840 is about 62.9826104688.

It can be divided in two parts, 249 and 840, that added together give a square (1089 = 33²).

The spelling of 249840 in words is "two hundred forty-nine thousand, eight hundred forty".