668194271 has 2 divisors, whose sum is σ = 668194272. Its totient is φ = 668194270.

The previous prime is 668194237. The next prime is 668194309. The reversal of 668194271 is 172491866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668194271 - 2⁶ = 668194207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668194201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334097135 + 334097136.

It is an arithmetic number, because the mean of its divisors is an integer number (334097136).

Almost surely, 2^668194271 is an apocalyptic number.

668194271 is a deficient number, since it is larger than the sum of its proper divisors (1).

668194271 is an equidigital number, since it uses as much as digits as its factorization.

668194271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 668194271 is about 25849.4539787594. The cubic root of 668194271 is about 874.2471983944.

The spelling of 668194271 in words is "six hundred sixty-eight million, one hundred ninety-four thousand, two hundred seventy-one".