249649 has 4 divisors (see below), whose sum is σ = 255780. Its totient is φ = 243520.

The previous prime is 249647. The next prime is 249659. The reversal of 249649 is 946942.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 946942 = 2 ⋅473471.

It can be written as a sum of positive squares in 2 ways, for example, as 30625 + 219024 = 175^2 + 468^2 .

It is a cyclic number.

It is not a de Polignac number, because 249649 - 2¹ = 249647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249647) 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 3 ways as a sum of consecutive naturals, for example, 3004 + ... + 3085.

It is an arithmetic number, because the mean of its divisors is an integer number (63945).

2²⁴⁹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

249649 is a deficient number, since it is larger than the sum of its proper divisors (6131).

249649 is an equidigital number, since it uses as much as digits as its factorization.

249649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6130.

The product of its digits is 15552, while the sum is 34.

The square root of 249649 is about 499.6488767124. The cubic root of 249649 is about 62.9665565338.

It can be divided in two parts, 24964 and 9, that multiplied together give a square (224676 = 474²).

The spelling of 249649 in words is "two hundred forty-nine thousand, six hundred forty-nine".