12170991 has 8 divisors (see below), whose sum is σ = 18546304. Its totient is φ = 6954840.

The previous prime is 12170989. The next prime is 12170999. The reversal of 12170991 is 19907121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12170991 - 2¹ = 12170989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12170999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289765 + ... + 289806.

It is an arithmetic number, because the mean of its divisors is an integer number (2318288).

Almost surely, 2^12170991 is an apocalyptic number.

12170991 is a deficient number, since it is larger than the sum of its proper divisors (6375313).

12170991 is an equidigital number, since it uses as much as digits as its factorization.

12170991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579581.

The product of its (nonzero) digits is 1134, while the sum is 30.

The square root of 12170991 is about 3488.6947415903. The cubic root of 12170991 is about 230.0251453290.

The spelling of 12170991 in words is "twelve million, one hundred seventy thousand, nine hundred ninety-one".