249705 has 24 divisors (see below), whose sum is σ = 449280. Its totient is φ = 128160.

The previous prime is 249703. The next prime is 249721. The reversal of 249705 is 507942.

It is not a de Polignac number, because 249705 - 2¹ = 249703 is a prime.

249705 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (249703) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1306 + ... + 1484.

It is an arithmetic number, because the mean of its divisors is an integer number (18720).

2²⁴⁹⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

249705 is a deficient number, since it is larger than the sum of its proper divisors (199575).

249705 is a wasteful number, since it uses less digits than its factorization.

249705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 249705 is about 499.7049129236. The cubic root of 249705 is about 62.9712642948.

The spelling of 249705 in words is "two hundred forty-nine thousand, seven hundred five".