668191219 has 2 divisors, whose sum is σ = 668191220. Its totient is φ = 668191218.

The previous prime is 668191217. The next prime is 668191241. The reversal of 668191219 is 912191866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668191219 - 2¹ = 668191217 is a prime.

It is a super-2 number, since 2×668191219² = 892959010297411922, which contains 22 as substring.

Together with 668191217, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (668191217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334095609 + 334095610.

It is an arithmetic number, because the mean of its divisors is an integer number (334095610).

Almost surely, 2^668191219 is an apocalyptic number.

668191219 is a deficient number, since it is larger than the sum of its proper divisors (1).

668191219 is an equidigital number, since it uses as much as digits as its factorization.

668191219 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 43.

The square root of 668191219 is about 25849.3949445630. The cubic root of 668191219 is about 874.2458673412.

The spelling of 668191219 in words is "six hundred sixty-eight million, one hundred ninety-one thousand, two hundred nineteen".