249961 has 4 divisors (see below), whose sum is σ = 251524. Its totient is φ = 248400.

The previous prime is 249947. The next prime is 249967. The reversal of 249961 is 169942.

It is a happy number.

249961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42025 + 207936 = 205^2 + 456^2 .

It is a cyclic number.

It is not a de Polignac number, because 249961 - 2⁷ = 249833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510 + ... + 871.

It is an arithmetic number, because the mean of its divisors is an integer number (62881).

2²⁴⁹⁹⁶¹ is an apocalyptic number.

It is an amenable number.

249961 is a deficient number, since it is larger than the sum of its proper divisors (1563).

249961 is a wasteful number, since it uses less digits than its factorization.

249961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1562.

The product of its digits is 3888, while the sum is 31.

The square root of 249961 is about 499.9609984789. The cubic root of 249961 is about 62.9927765297.

The spelling of 249961 in words is "two hundred forty-nine thousand, nine hundred sixty-one".