249531 has 4 divisors (see below), whose sum is σ = 332712. Its totient is φ = 166352.

The previous prime is 249521. The next prime is 249533. The reversal of 249531 is 135942.

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 249531 - 2⁵ = 249499 is a prime.

It is a super-2 number, since 2×249531² = 124531439922, which contains 22 as substring.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (249533) 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, 41586 + ... + 41591.

It is an arithmetic number, because the mean of its divisors is an integer number (83178).

2²⁴⁹⁵³¹ is an apocalyptic number.

249531 is a deficient number, since it is larger than the sum of its proper divisors (83181).

249531 is an equidigital number, since it uses as much as digits as its factorization.

249531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83180.

The product of its digits is 1080, while the sum is 24.

The square root of 249531 is about 499.5307798324. The cubic root of 249531 is about 62.9566343035.

It can be divided in two parts, 249 and 531, that added together give a triangular number (780 = T₃₉).

The spelling of 249531 in words is "two hundred forty-nine thousand, five hundred thirty-one".