12191947 has 2 divisors, whose sum is σ = 12191948. Its totient is φ = 12191946.

The previous prime is 12191917. The next prime is 12192017. The reversal of 12191947 is 74919121.

It is a weak prime.

It is an emirp because it is prime and its reverse (74919121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12191947 - 2¹⁹ = 11667659 is a prime.

It is not a weakly prime, because it can be changed into another prime (12191917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6095973 + 6095974.

It is an arithmetic number, because the mean of its divisors is an integer number (6095974).

Almost surely, 2^12191947 is an apocalyptic number.

12191947 is a deficient number, since it is larger than the sum of its proper divisors (1).

12191947 is an equidigital number, since it uses as much as digits as its factorization.

12191947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 34.

The square root of 12191947 is about 3491.6968654223. The cubic root of 12191947 is about 230.1570886522.

It can be divided in two parts, 1219194 and 7, that multiplied together give a palindrome (8534358).

The spelling of 12191947 in words is "twelve million, one hundred ninety-one thousand, nine hundred forty-seven".