249981 has 8 divisors (see below), whose sum is σ = 336960. Its totient is φ = 164832.

The previous prime is 249973. The next prime is 249989. The reversal of 249981 is 189942.

It is an interprime number because it is at equal distance from previous prime (249973) and next prime (249989).

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

It is not a de Polignac number, because 249981 - 2³ = 249973 is a prime.

It is a super-2 number, since 2×249981² = 124981000722, which contains 22 as substring.

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 249981.

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 (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (42120).

2²⁴⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

249981 is a deficient number, since it is larger than the sum of its proper divisors (86979).

249981 is a wasteful number, since it uses less digits than its factorization.

249981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915.

The product of its digits is 5184, while the sum is 33.

The square root of 249981 is about 499.9809996390. The cubic root of 249981 is about 62.9944565543.

The spelling of 249981 in words is "two hundred forty-nine thousand, nine hundred eighty-one".