991275 has 12 divisors (see below), whose sum is σ = 1639032. Its totient is φ = 528640.

The previous prime is 991273. The next prime is 991313. The reversal of 991275 is 572199.

It is not a de Polignac number, because 991275 - 2¹ = 991273 is a prime.

It is a super-2 number, since 2×991275² = 1965252251250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991273) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6534 + ... + 6683.

It is an arithmetic number, because the mean of its divisors is an integer number (136586).

2⁹⁹¹²⁷⁵ is an apocalyptic number.

991275 is a deficient number, since it is larger than the sum of its proper divisors (647757).

991275 is a wasteful number, since it uses less digits than its factorization.

991275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13230 (or 13225 counting only the distinct ones).

The product of its digits is 5670, while the sum is 33.

The square root of 991275 is about 995.6279425569. The cubic root of 991275 is about 99.7083167024.

The spelling of 991275 in words is "nine hundred ninety-one thousand, two hundred seventy-five".