991249 has 16 divisors (see below), whose sum is σ = 1238400. Its totient is φ = 774144.

The previous prime is 991229. The next prime is 991261. The reversal of 991249 is 942199.

It is not a de Polignac number, because 991249 - 2⁵ = 991217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3729 + ... + 3985.

It is an arithmetic number, because the mean of its divisors is an integer number (77400).

2⁹⁹¹²⁴⁹ is an apocalyptic number.

It is an amenable number.

991249 is a deficient number, since it is larger than the sum of its proper divisors (247151).

991249 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (991248) it forms an eRAP, since the sums of their prime factors are consecutive (311 and 312).

991249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312.

The product of its digits is 5832, while the sum is 34.

The square root of 991249 is about 995.6148853849. The cubic root of 991249 is about 99.7074449501.

The spelling of 991249 in words is "nine hundred ninety-one thousand, two hundred forty-nine".