249841 has 4 divisors (see below), whose sum is σ = 250852. Its totient is φ = 248832.

The previous prime is 249833. The next prime is 249853. The reversal of 249841 is 148942.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 148942 = 2 ⋅74471.

It can be written as a sum of positive squares in 2 ways, for example, as 156816 + 93025 = 396^2 + 305^2 .

It is a 3-Lehmer number, since φ(249841) divides (249841-1)³.

It is a cyclic number.

It is not a de Polignac number, because 249841 - 2³ = 249833 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145 + ... + 721.

It is an arithmetic number, because the mean of its divisors is an integer number (62713).

It is a Poulet number, since it divides 2²⁴⁹⁸⁴⁰-1.

2²⁴⁹⁸⁴¹ is an apocalyptic number.

It is an amenable number.

249841 is a deficient number, since it is larger than the sum of its proper divisors (1011).

249841 is an equidigital number, since it uses as much as digits as its factorization.

249841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010.

The product of its digits is 2304, while the sum is 28.

The square root of 249841 is about 499.8409747110. The cubic root of 249841 is about 62.9826944993.

The spelling of 249841 in words is "two hundred forty-nine thousand, eight hundred forty-one".