249861 has 8 divisors (see below), whose sum is σ = 342304. Its totient is φ = 162000.

The previous prime is 249859. The next prime is 249863. The reversal of 249861 is 168942.

It is an interprime number because it is at equal distance from previous prime (249859) and next prime (249863).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 249861 - 2¹ = 249859 is a prime.

It is a Duffinian number.

249861 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 249861.

It is not an unprimeable number, because it can be changed into a prime (249863) 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 7 ways as a sum of consecutive naturals, for example, 1015 + ... + 1236.

It is an arithmetic number, because the mean of its divisors is an integer number (42788).

2²⁴⁹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

249861 is a deficient number, since it is larger than the sum of its proper divisors (92443).

249861 is a wasteful number, since it uses less digits than its factorization.

249861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2291.

The product of its digits is 3456, while the sum is 30.

The square root of 249861 is about 499.8609806736. The cubic root of 249861 is about 62.9843750619.

The spelling of 249861 in words is "two hundred forty-nine thousand, eight hundred sixty-one".