249905 has 8 divisors (see below), whose sum is σ = 302784. Its totient is φ = 198000.

The previous prime is 249881. The next prime is 249911. The reversal of 249905 is 509942.

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

It is not a de Polignac number, because 249905 - 2¹⁶ = 184369 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 249905.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 590 + ... + 920.

It is an arithmetic number, because the mean of its divisors is an integer number (37848).

2²⁴⁹⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

249905 is a deficient number, since it is larger than the sum of its proper divisors (52879).

249905 is a wasteful number, since it uses less digits than its factorization.

249905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 249905 is about 499.9049909733. The cubic root of 249905 is about 62.9880719838.

The spelling of 249905 in words is "two hundred forty-nine thousand, nine hundred five".