249745 has 8 divisors (see below), whose sum is σ = 302400. Its totient is φ = 198000.

The previous prime is 249737. The next prime is 249749. The reversal of 249745 is 547942.

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

It is not a de Polignac number, because 249745 - 2³ = 249737 is a prime.

249745 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (249749) 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, 870 + ... + 1120.

It is an arithmetic number, because the mean of its divisors is an integer number (37800).

2²⁴⁹⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

249745 is a deficient number, since it is larger than the sum of its proper divisors (52655).

249745 is a wasteful number, since it uses less digits than its factorization.

249745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455.

The product of its digits is 10080, while the sum is 31.

The square root of 249745 is about 499.7449349418. The cubic root of 249745 is about 62.9746265504.

The spelling of 249745 in words is "two hundred forty-nine thousand, seven hundred forty-five".