12191755 has 4 divisors (see below), whose sum is σ = 14630112. Its totient is φ = 9753400.

The previous prime is 12191741. The next prime is 12191779. The reversal of 12191755 is 55719121.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 12191755 - 2¹⁵ = 12158987 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1219171 + ... + 1219180.

It is an arithmetic number, because the mean of its divisors is an integer number (3657528).

Almost surely, 2^12191755 is an apocalyptic number.

12191755 is a deficient number, since it is larger than the sum of its proper divisors (2438357).

12191755 is an equidigital number, since it uses as much as digits as its factorization.

12191755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2438356.

The product of its digits is 3150, while the sum is 31.

The square root of 12191755 is about 3491.6693715184. The cubic root of 12191755 is about 230.1558804669.

The spelling of 12191755 in words is "twelve million, one hundred ninety-one thousand, seven hundred fifty-five".