249691 has 4 divisors (see below), whose sum is σ = 268912. Its totient is φ = 230472.

The previous prime is 249677. The next prime is 249703. The reversal of 249691 is 196942.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 249691 - 2⁵ = 249659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9591 + ... + 9616.

It is an arithmetic number, because the mean of its divisors is an integer number (67228).

2²⁴⁹⁶⁹¹ is an apocalyptic number.

249691 is a deficient number, since it is larger than the sum of its proper divisors (19221).

249691 is a wasteful number, since it uses less digits than its factorization.

249691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19220.

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

The square root of 249691 is about 499.6909044599. The cubic root of 249691 is about 62.9700874206.

The spelling of 249691 in words is "two hundred forty-nine thousand, six hundred ninety-one".