991197 has 12 divisors (see below), whose sum is σ = 1485120. Its totient is φ = 660636.

The previous prime is 991187. The next prime is 991201. The reversal of 991197 is 791199.

It is not a de Polignac number, because 991197 - 2⁴ = 991181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991127) 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, 1797 + ... + 2282.

It is an arithmetic number, because the mean of its divisors is an integer number (123760).

2⁹⁹¹¹⁹⁷ is an apocalyptic number.

It is an amenable number.

991197 is a deficient number, since it is larger than the sum of its proper divisors (493923).

991197 is an equidigital number, since it uses as much as digits as its factorization.

991197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4094 (or 4082 counting only the distinct ones).

The product of its digits is 5103, while the sum is 36.

The square root of 991197 is about 995.5887705273. The cubic root of 991197 is about 99.7057013997.

It can be divided in two parts, 99 and 1197, that added together give a 4-th power (1296 = 6⁴).

The spelling of 991197 in words is "nine hundred ninety-one thousand, one hundred ninety-seven".