249985 has 12 divisors (see below), whose sum is σ = 320508. Its totient is φ = 187136.

The previous prime is 249973. The next prime is 249989. The reversal of 249985 is 589942.

It can be written as a sum of positive squares in 6 ways, for example, as 50176 + 199809 = 224^2 + 447^2 .

It is not a de Polignac number, because 249985 - 2⁷ = 249857 is a prime.

It is a Duffinian number.

249985 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (249989) 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 11 ways as a sum of consecutive naturals, for example, 1359 + ... + 1531.

It is an arithmetic number, because the mean of its divisors is an integer number (26709).

2²⁴⁹⁹⁸⁵ is an apocalyptic number.

249985 is the 289-th octagonal number.

It is an amenable number.

249985 is a deficient number, since it is larger than the sum of its proper divisors (70523).

249985 is a wasteful number, since it uses less digits than its factorization.

249985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 195 counting only the distinct ones).

The product of its digits is 25920, while the sum is 37.

The square root of 249985 is about 499.9849997750. The cubic root of 249985 is about 62.9947925485.

The spelling of 249985 in words is "two hundred forty-nine thousand, nine hundred eighty-five".